Echinoderm Anatomy and Development Ontology
definition
The official definition, explaining the meaning of a class or property. Shall be Aristotelian, formalized and normalized. Can be augmented with colloquial definitions.
2012-04-05: Barry Smith The official OBI definition, explaining the meaning of a class or property: 'Shall be Aristotelian, formalized and normalized. Can be augmented with colloquial definitions' is terrible. Can you fix to something like: A statement of necessary and sufficient conditions explaining the meaning of an expression referring to a class or property. Alan Ruttenberg Your proposed definition is a reasonable candidate, except that it is very common that necessary and sufficient conditions are not given. Mostly they are necessary, occasionally they are necessary and sufficient or just sufficient. Often they use terms that are not themselves defined and so they effectively can't be evaluated by those criteria. On the specifics of the proposed definition: We don't have definitions of 'meaning' or 'expression' or 'property'. For 'reference' in the intended sense I think we use the term 'denotation'. For 'expression', I think we you mean symbol, or identifier. For 'meaning' it differs for class and property. For class we want documentation that let's the intended reader determine whether an entity is instance of the class, or not. For property we want documentation that let's the intended reader determine, given a pair of potential relata, whether the assertion that the relation holds is true. The 'intended reader' part suggests that we also specify who, we expect, would be able to understand the definition, and also generalizes over human and computer reader to include textual and logical definition. Personally, I am more comfortable weakening definition to documentation, with instructions as to what is desirable. We also have the outstanding issue of how to aim different definitions to different audiences. A clinical audience reading chebi wants a different sort of definition documentation/definition from a chemistry trained audience, and similarly there is a need for a definition that is adequate for an ontologist to work with.
PERSON:Daniel Schober
An alternative label for a class or property which has the exact same meaning than the preferred name/primary label.
has exact synonym
is part of
my brain is part of my body (continuant parthood, two material entities)
my stomach cavity is part of my stomach (continuant parthood, immaterial entity is part of material entity)
this day is part of this year (occurrent parthood)
a core relation that holds between a part and its whole
Everything is part of itself. Any part of any part of a thing is itself part of that thing. Two distinct things cannot be part of each other.
Occurrents are not subject to change and so parthood between occurrents holds for all the times that the part exists. Many continuants are subject to change, so parthood between continuants will only hold at certain times, but this is difficult to specify in OWL. See http://purl.obolibrary.org/obo/ro/docs/temporal-semantics/
Parthood requires the part and the whole to have compatible classes: only an occurrent can be part of an occurrent; only a process can be part of a process; only a continuant can be part of a continuant; only an independent continuant can be part of an independent continuant; only an immaterial entity can be part of an immaterial entity; only a specifically dependent continuant can be part of a specifically dependent continuant; only a generically dependent continuant can be part of a generically dependent continuant. (This list is not exhaustive.) A continuant cannot be part of an occurrent: use 'participates in'. An occurrent cannot be part of a continuant: use 'has participant'. A material entity cannot be part of an immaterial entity: use 'has location'. A specifically dependent continuant cannot be part of an independent continuant: use 'inheres in'. An independent continuant cannot be part of a specifically dependent continuant: use 'bearer of'.
part_of
part of
X immediately_preceded_by Y iff: end(X) simultaneous_with start(Y)
immediately preceded by
x develops from y if and only if either (a) x directly develops from y or (b) there exists some z such that x directly develops from z and z develops from y
This is the transitive form of the develops from relation
develops from
x existence starts during y if and only if the time point at which x starts is after or equivalent to the time point at which y starts and before or equivalent to the time point at which y ends. Formally: x existence starts during y iff α(x) >= α(y) & α(x) <= ω(y).
Relation between continuant c and occurrent s, such that every instance of c ceases to exist during some s, if it does not die prematurely.
x existence ends during y if and only if the time point at which x ends is before or equivalent to the time point at which y ends and after or equivalent to the point at which y starts. Formally: x existence ends during y iff ω(x) <= ω(y) and ω(x) >= α(y).
The relations here were created based on work originally by Fabian Neuhaus and David Osumi-Sutherland. The work has not yet been vetted and errors in definitions may have occurred during transcription.
root node
Biological process during which certain cells of a female or male individual (parent) are transformed into specialized reproductive cells (gametes) that will initiate development of a progeny individual (offspring) upon fertilization.
Period during which female gametes (or oocytes, or eggs) develop and mature from primordial female germ cells to generate cells competent to further development upon fertilization by a mature spermatozoid.
A female gamete that is small in size, i.e. about 10 microm in diameter, and that is at the previtellogenic stage.
A developing female gamete that started growing in size by accumulation of yolk proteins. At this stage, it is characterized by the presence of a large nucleus, the germinal vesicle, which contains a prominent nucleolus and occupies most of the cytoplasm.
A developing female gamete that has reached its full size. It has grown up to ten times its original size, i.e. 80 to 100microm. It also displays a large germinal vesicle that is centered, but it is still not competent for fertilization.
fully grown oocyte with centered germinal vesicle stage
A developing female gamete that has reached its full size and in which the germinal vesicle has moved asymmetrically to the cell periphery. The germinal vesicle is now close to the animal pole.
fully grown oocyte with off-centered germinal vesicle stage
A developing female gamete in which the germinal vesicle has broken down. The germinal vesicle is no longer visible. However, the female gamete is still not mature. It is undergoing meiotic maturation, extruding successively a first and a second polar body.
fully grown oocyte with no nucleus stage
A mature female gamete that has achieved its meiotic maturation and in which the female pronucleus is visible. The mature oocyte is arrested in G1 phase and its average size is 80 to 100 ÃƒÂ‚Ã‚Âµm. It is surrounded by a transparent jelly coat that is about 30 ÃƒÂ‚Ã‚Âµm thick. It is competent to fertilization and it is located in the female gonad where it may be stored for weeks to months before its release in sea water by spawning. In the P. lividus species, the mature female gametes are characterized by the presence of pigment granules concentrated in a subequatorial band. This band is classically called the pigment band and allows to visualize the first embryonic axis, i.e. the animal-vegetal axis, which is perpendicular to the band.
Period during which male gametes (or spermatozoa, or spermatozoid) develop and mature from primordial male germ cells to generate cells competent to further development upon fertilization of a mature oocyte.
A developing, immature male gamete undergoing mitosis and meiosis to ultimately produce mature spermatozoa.
A mature male gamete that is composed of a head, encompassing a compact nucleus, a neck, a middle piece, and a tail (or flagellum) that propels it towards the oocyte upon spawning.
Biological process during which the embryo forms. This process starts with the fertilization of a mature oocyte by a mature spermatozoid. It is characterized by a succession of rapid mitotic divisions with no significant growth, but with axis establishment and cellular differentiation, thereby leading to the development of a multicellular embryo.
A fertilized egg, right after fertilization. The embryo is characterized morphologically by the fact that it is a single diploid cell surrounded by a fertilization envelope. This stage corresponds to an embryo of age 0 hour post-fertilization.
Period during which the fertilized egg undergoes a succession of rapid cell divisions with no significant growth.
An embryo that is composed of two cells and is surrounded by a fertilization envelope. The first cleavage plane took place meridionally (i.e. along the animal-vegetal axis), thereby generating two blastomeres of equal size, each containing both animal and vegetal cytoplasm.
An embryo that is composed of four cells and is surrounded by a fertilization envelope. The second cleavage plane was meridional and perpendicular to the first one, thereby producing four blastomeres of equal size, each containing both animal and vegetal cytoplasm.
An embryo that is composed of eight cells and is surrounded by a fertilization envelope. The third cleavage took place perpendicular to the first two cleavage planes and was equatorial. It thus generated an animal and a vegetal hemisphere each composed of a quartet of four cells of equal volume.
An embryo that is composed of 16 cells and is surrounded by a fertilization envelope. Note for euechinoid indirect developers: although the fourth cleavage occurred simultaneously in all cells, the pattern of cell division differed in the animal and vegetal blastomeres. In the animal hemisphere the four cells divided meridionally, producing eight blastomeres of equal volume arrayed in a single tier. These cells are called the mesomeres. In the vegetal hemisphere, the four cells underwent an unequal, equatorial cleavage, producing a tier of four large cells, the macromeres, and a tier of four small cells, the micromeres, located at the vegetal pole. At the 16-cell stage, the embryo is hence composed of three groups of cells with distinct sizes. In most sea urchin species,this is the first morphological indication of the animal-vegetal axis.
An embryo that is composed of 28 cells and is surrounded by a fertilization envelope. Note for euechinoid indirect developers: In most sea urchin species, the fifth cleavage signed the end of cell division synchrony, with the mesomeres and macromeres dividing prior to the micromeres with a significant time difference. In the animal hemisphere, the mesomeres underwent an equal and equatorial cleavage, giving rise to two animal cell tiers, each composed of eight blastomeres of equal size: the an1 tier located at the animal pole and the an2 tier located below an1. In parallel, the macromeres divided meridionally, forming a ring of eight cells of equal volume located below the an2 tier. At that stage, the micromeres have not yet divided and are still at a number of four cells.
An embryo that is composed of 32 cells and is surrounded by a fertilization envelope. Note for euechinoid indirect developers: The micromeres have undergone a fifth cleavage (and this has occurred prior to a subsequent division of the other cells). This cleavage was unequal and equatorial, thereby producing four large micromeres and four small micromeres, the smallest cells still marking the vegetal pole.
An embryo that is composed of 56 cells and is surrounded by a fertilization envelope. Note for euechinoid indirect developers: In the animal hemisphere, cells of the an1 and an2 tiers underwent an additional meridional division, producing tiers composed of 16 cells. The macromeres divided equatorially and equally, generating two vegetal cell tiers, each composed of 8 cells of equal volume, namely the veg1 tier (located below an2) and the veg2 tier (located below veg1 and above the large micromeres). At that stage, the large and small micromeres (4 cells each) have not undergone yet a sixth division.
An embryo that is composed of 60 cells and is surrounded by a fertilization envelope. Note for euechinoid indirect developers: The large micromeres have achieved a sixth cleavage, which was meridional, thereby generating a ring of 8 cells. At that stage, from the animal to the vegetal pole, the embryo is composed of: 16 an1-cells, 16 an2-cells, 8 veg1-cells, 8 veg2-cells, 8 large micromeres and 4 small micromeres.
Period during which the embryo is transformed into a hollow sphere that is one cell layer thick and encompasses a central, fluid-filled cavity called the blastocoel. During this period, every cell of the embryo is in contact on the inside with the blastocoel and on the outside with the hyaline layer.
The embryo is composed of 110-120 cells, as most blastomeres have completed an additional mitotic division after the 60-cell stage. The embryo is surrounded by a fertilization envelope. All cells are about the same size and there are no obvious morphological indications of embryonic polarity or embryonic territories. All cells have begun to acquire apico-basal polarity, and the embryo is beginning to transform into a hollow sphere with a wall that is one cell layer thick and a fluid-filled cavity (the blastocoel) in the center. Note for euechinoid indirect developers: the micromere progeny divide more slowly than other cells of the embryo. Molecular labelling typically indicates the presence of 8 large micromere descendants and 4 small micromeres at this stage .
The embryo is composed of slightly more than 200 cells, as most blastomeres have completed an additional mitotic division after the very early blastula stage. The embryo is surrounded by a fertilization envelope. The embryo remains spherical and one cell layer thick, and the blastocoel has expanded slightly since the very early blastula stage, without increasing though the size of the embryo. The synchrony of cell divisions between animal and vegetal cell tiers, as well as within cell tiers, is becoming less pronounced. Note for euechinoid indirect developers: Molecular labeling typically indicates the presence of 16 large micromere descendants and 4 small micromeres at this stage .
The embryo is composed of about 300 cells and is surrounded by a fertilization envelope. Cell divisions are less synchronous than at earlier stages. The cells have flattened slightly on their inner (basal) surface, further contributing to the enlargement of the blastocoel. In some species, cells have started to form cilia on their outer surface. The embryo is still spherical and does not display any obvious morphological landmarks that indicate the primary or secondary embryonic axes. Note for euechinoid indirect developers: molecular labeling typically indicates the presence of 16 to 32 large micromere descendant cells and 4 to 8 small micromere descendants at this stage .
The embryo is composed of about 400 cells and is surrounded by a fertilization envelope. The embryo is still spherical but the wall is thinner and smoother than at previous stages. The vegetal plate has not formed. Many cells are ciliated, and in some species (e.g. P. lividus) the embryo has begun to rotate within the fertilization envelope, while in others (e.g. S. purpuratus) it is still non-motile. Note for euechinoid indirect developers: molecular labeling typically indicates the presence of 32 large micromere descendants and 4 to 8 small micromere descendants at this stage .
The embryo is composed of about 800 cells and is surrounded by a fertilization envelope. The fertilization envelope has started to break down due to the secretion by ectodermal cells of the hatching enzyme, a metalloprotease that digests the fertilization envelope and frees the embryo. The vegetal plate has not formed. The embryo rotates within the envelope or swims away as soon as it is free. At the animal pole, a tuft of long and immotile cilia has started growing.
The embryo has hatched from the fertilization envelope and swims freely. It is still a hollow sphere that is one cell layer thick, but the cells constituting the vegetal plate (i.e. located at the vegetal pole) have started thickening along the apico-basal axis, thereby creating a morphological landmark that enables orienting the embryo along the animal-vegetal axis. In addition, at the animal pole, the apical tuft composed of long and immotile cilia has continued expending.
The embryo has started elongated along the animal-vegetal axis. Its vegetal region has further continued to thicken and it is marked by a characteristic 'V' shape formed by the blastocoel at the level of the cells constituting the vegetal plate, thereby pointing to the vegetal pole. At the animal pole, the embryo is characterized by the presence of an apical tuft.
Period during which complex and coordinated cellular movements take place and ultimately generate a three-layered embryo with inner tissues. A portion of cells will ingress, invaginate and/or migrate within the embryo and form the two inner layers (i.e. the endoderm and the mesoderm). The cells that remained outside will instead spread over the whole surface of the embryo and form the outer layer (i.e. the ectoderm).
The phase during which skeletogenic primary mesenchyme cells (PMCs) move from the vegetal plate into the blastocoel (ingress) but before the vegetal plate has started to invaginate.
The vegetal plate is apparent and skeletogenic primary mesenchyme cells (PMCs) are in the process of ingression, a type of epithelialÃƒÂ¢Ã¢Â‚Â¬Ã¢Â€Âœmesenchymal transition (EMT). The epithelial wall of the embryo has thickened at the animal pole, where a tuft of long, non-motile cilia has formed.
All skeletogenic primary mesenchyme cells (PMCs) have ingressed into the blastocoel, leaving behind a reformed vegetal plate containing at its center the 8 small micromere descendants surrounded by non-skeletogenic mesoderm cells. The PMCs are organized in a mound on the vegetal plate but have not begun to disperse. The thickened apical pole domain with its tuft of long, non-motile cilia is still apparent.
The skeletogenic primary mesenchyme cells (PMCs) have migrated away from the vegetal plate by extending filopodia and moving along the blastocoel wall. The vegetal plate has flattened but has not started to invaginate. The apical pole domain still bears an apical tuft of long, non-motile cilia.
Period during which the inpocketing and elongation of the archenteron takes place.
The embryo is characterized morphologically by a slight invagination of the vegetal plate and the dispersal of the skeletogenic primary mesenchyme cells (PMCs) along the blastocoel wall at the periphery of the invaginating region. The PMCs are just beginning to adopt a characteristic, ring-like arrangement near the equator of the embryo. Within the vegetal plate, the peripheral non-skeletogenic mesoderm cells have started to indent, undergoing important cell shape changes, but the center of the vegetal plate (composed of small micromeres) has not started to elevate. Invagination has generated the blastopore (an opening that will give rise to the larval anus) as well as the anterior portion of the archenteron (a region that will give rise to the coelomic pouches). At the animal pole, the apical pole domain is still marked by an enlarged epithelium bearing long and immotile cilia.
The embryo is mainly characterized morphologically by the presence in the blastocoel of a small archenteron (i.e. primitive digestive tract) that is about a third of its finally size. Following the initial invagination of the vegetal plate, the archenteron has slightly been extended, within the blastocoel, by the subsequent invagination of additional non-skeletogenic mesoderm cells and of some endoderm cells. In parallel, the skeletogenic mesenchyme cells (or SM cells, primary mesenchyme cells or PMC) have by now started migrating along the blastocoel wall, towards the animal pole, thereby creating two lateral chains (one left and one right), while around the developing archenteron, they have gathered into two ventrolateral clusters separated by an oral (or ventral) and an aboral (or dorsal) chain defined by the remaining skeletogenic mesenchyme cells. Within the oral and aboral skeletogenic mesenchyme chains, the cells have further started to fuse to form syncytial filopodial cables within which skeletal calcification will subsequently take place. At the animal pole, the animal neuroectoderm territory is still marked by an enlarged epithelium bearing long and immotile cilia.
The embryo is mainly characterized morphologically by the presence of an archenteron (i.e. primitive digestive tract) that has reached one-half its way into the blastocoel. A second phase of archenteron elongation has taken place by invagination of additional cells into the blastocoel, by cell division or by convergent-extension movements depending on the sea urchin species. Non-skeletogenic mesoderm cells that are present at the tip of the archenteron have further started ingressing into the blastocoel, generating the non-skeletogenic mesenchyme cells (or NSM cells, secondary mesenchyme cells or SMC). The oral ectoderm has also started to flatten and to become thicker, providing the first morphological indicator of the oral-aboral (or ventro-dorsal) axis of the embryo. As a consequence the oral chain formed by a portion of the skeletogenic mesenchyme cells has also flattened. Finally, skeletal calcification has further begun within the skeletogenic mesenchyme ventrolateral clusters, marked by the presence of the first calcified structures, which appear as small dots at that stage. At the animal pole, the animal neuroectoderm territory is still marked by an enlarged epithelium bearing long and immotile cilia.
The embryo is mainly characterized morphologically by the presence in the blastocoel of a fully extended archenteron (i.e. primitive digestive tract) that has now reached the roof of the blastocoel. The third and last extension phase of the archenteron has been ensured by pulling forces exerted by non-skeletogenic mesoderm cells that are still present at the tip of the archenteron. These cells have produced filopodia that extended towards the animal pole, attached the wall, and then shortened, thereby pulling up the archenteron. In some sea urchin species, this pulling force is already orienting the tip of the archenteron towards the oral ectoderm, where the future mouth of the larvae will form. In parallel, in the blastocoel, additional non-skeletogenic mesoderm cells continued ingressing from the tip of the archenteron and the skeletal calcified structures present in the skeletogenic mesenchyme ventrolateral clusters have further grown, forming now the primary triradiate skeletal rudiments (or spicules). At the animal pole, the animal neuroectoderm territory is still marked by an enlarged epithelium bearing long and immotile cilia.
The embryo is mainly characterized morphologically by a typical triangular shape, the beginning of the tripatition of the digestive tract and the presence of pigmented cells. The oral (or ventral) ectoderm has by now even more flattened, making an almost perfect right angle with the blastoporal side of the embryo. By contrast, on the opposite side, the aboral (or dorsal) ectoderm has round up and slightly elongated, thereby forming the primitive apex of the future larvae. These changes have conferred the embryo a typical and easy recognizable triangular shape. In the oral ectoderm, a small depression has further appeared, called the stomodeum, which will later fuse with the tip of the archenteron to form the mouth. In the blastocoel, the digestive tract has also by now bended toward the stomodeum and started to become tripartite. The cardiac sphincter has started forming, separating the future esophagus from the future stomach. The triradiate spicules have also continued elongating, thereby forming by now, towards the animal pole, the right and left dorsoventral connecting rods, towards the apex, the body rods, and along the vegetal, oral ectoderm the left and right ventral transverse rods. Moreover, some non-skeletogenic mesenchyme cells (or NSM cells, secondary mesenchyme cells or SMC) have started becoming pigmented and inserted into the aboral ectoderm. These cells represent part of the future immune system of the larvae along with other blastocoelar cells that are present in the blastocoel around the gut. In the vicinity of the future esophagus, other non-skeletogenic mesoderm descendant cells along with some endoderm cells have further arranged to form a single unpaired coelomic pouch. At the animal pole, the apical pole domain has also started to flatten making the embryo look like a square when viewed from the oral side, and it still arbors a tuft a long and immotile cilia. Finally, within the apical pole domain, but not yet in the ciliary band, molecular labeling surveys also start by this stage to reveal the presence of differentiating neuronal cells.
Biological process during which the specific outcome is the progression of a free-living larva before the development of the adult. Indirect development represents the mainstream developmental mode of metazoans. This process usually starts with the emergence of a larva that is planktonic and stops at the end of metamorphosis once the animal assumes adult characters.
The embryo is by now a fully formed pluteus larva. The mouth has opened and the digestive tract is becoming functional. On the ventral side, the mouth is surrounded anteriorly by an oral hood and posteriorly by two postoral arms. On the dorsal side, the apex has lengthened. The skeleton has indeed continued extending, expending the dorsoventral connecting rods, the body rods, and the ventral transverse rods as well as developing the anterolateral rods and the postoral rods. Within the larva, the tripartition of the digestive tract has further progressed. The cardiac sphincter is now fully formed in between the esophagus and the stomach, and the pyloric sphincter in between the stomach and the intestine and the anal sphincter at the level of the anus have also started forming. Around the esophagus, the coelomic pouch has further developed into two bilobed sacs (or pouches), one on each side of the digestive tract. Finally, within the apical pole domain, as well as within the ciliary band, differentiated neurons with their extended axons can also now be distinguished by immunostaining. In parallel, the apical tuft of long and immotile cilia remains discernable at the tip of the oral hood, while in parallel the ciliary band has further started growing a concentrated number of intermediate size motile cilia, which will be used by the larva to swim directionally.
The 4-arm pluteus larva is mainly characterized morphologically by the presence, on the ventral side, of four extended arms (two anterolateral arms at the level of the oral hood and two postoral arms) and on the dorsal side by a sleeked apex. The larva now possesses a completely tripartite and functional digestive tract composed of an esophagus, a stomach, and an intestine, respectively limited by a cardiac sphincter, a pyloric sphincter, and an anal sphincter. Around the esophagus, the right and left coelomic pouches have further started to grow in size and elongate. The first morphological indicator of a left-right asymmetry becomes apparent at that stage, the left coelomic pouch being slightly more elongated than the right one. Furthermore, a thin protrusion of non-skeletogenic mesenchyme cells can be seen extending from the left coelomic pouch to the anterior ectoderm. This is the primary pore canal, which opens to the exterior environment by the hydropore. The larva further now possesses, all around the esophagus, a network of contractile muscles allowing it to swallow and feed. Finally, the apical tuft previously observed at the animal pole has by now disappeared, leaving behind only the concentrated stretch of intermediate size cilia borne by the ciliary band.
The 6-arm pluteus larva is mainly characterized morphologically by the presence, on the ventral side, of six arms, and by the development, on the anterior midline of the esophagus, of the dorsal arch. The larva has indeed extended on the ventral side two additional posterodorsal arms and has developed on the anterior side an additional skeletal element called the dorsal arch. In addition, at the basis of the postoral and posterodorsal arms, four small patches of ciliary band have by now cut off and migrated toward the apex, forming four patches of ciliated structures called the epaulettes (one posterior and one anterior pair). The nervous system of the larva has also become more complex with cell bodies and axons being present all along the arms and for the latter as well throughout the apex. The left and right coelomic pouches have continued to elongate on each side of the digestive tract. As a note this stage is relatively fleeting.
The 8-arm pluteus larva is mainly characterized morphologically by the presence on the ventral side of the larva of eight arms and by the development within the larva, on the left side of the stomach, of the adult rudiment. This stage is relatively long. It includes distinct changes occurring to the larva as well as within the larva, although the larva consistently exhibits 8 arms. In addition, it should be highlighted that the sequence of events taking place at the level of the larva compared to that occurring on the left side of the stomach to form the rudiment are heterochronic, meaning that differences are observed among individuals in the relative timing of these events. From the larval point of view, at that stage, on the anterior side, the dorsal arch has extended out of the oral hood, thereby forming two additional arms above the mouth, i.e. the preoral arms. In parallel, across the apex, the epaulettes have continued developing, thereby generating four large structures rich in cilia and perpendicular to the ventro-dorsal axis. At the tip of the apex, the suture of the body rods has also eventually ruptured, considerably enlarging the larval apex and reducing the angle between the postoral and posterodorsal arms. In parallel, inside the larva, the left coelomic pouch has also by now been partitioned into three parts: the axocoel (upper part, close to the esophagus), the hydrocoel (middle part) and the somatocoel (lower part, next to the stomach). Likewise, on the opposite side, the right coelomic pouch has also been partitioned into a right axohydrocoel and a right somatocoel, although the right axohydrocoel remains in a rudimentary state compared to its left counterparts. In addition, at the basis of the posterodorsal arm on the left side, a small portion of the ectoderm has thickened, invaginated, and came into contact with the left hydocoel. This structure is called the vestibule and together with the left hydrocoel and the left stomatocoel they have further subsequently fused to form the adult rudiment. The formation of the rudiment has overall taken some time, giving rise first to a pentaradial disc and then to a pentaradial complex structure harboring podia (i.e. tube feet) and spines. In parallel, on the right size of the larva, a variable number of pedicellariae (one to four) and endoskeletal elements (i.e. the five genital plates) have further formed, which will also later contribute to the composition of the adult body.
The competent pluteus larva is mainly characterized morphologically by the presence, on the ventral size, of still 8 arms and by the presence on the left side of the stomach of the rudiment that is now the size of or even bigger than the stomach. The rudiment further harbors by now five long primary podia (i.e. tube feet), five quartets of definitive spines located between the primary podia and five pairs of immature spines at the basis of the primary podia, while on the opposite side, i.e. on the right side of the larva, five to seven immature spines have further developed, supported by the genital plates, along with one to four pedicaellariae. At the level of the larva, in parallel, the anterior and posterior pairs of epaulettes have also considerably increased in size by now and even fused dorsally to the hydropore and to the anus respectively, thereby leaving exempt of cilia two lateral fields in between them. At the center of the left lateral field, the vestibular roof has also by now ruptured and this opening has created the vestibular pore, through which some primary podia of the rudiment protrude outside the larva and scrutinize the substrate looking for the adequate cues to begin metamorphosis. At that stage, the larva is thus exhibiting a typical substrate-test behavior, going to the sea bottom and scrutinizing the substrate. This behavior is characteristic of a larva named competent to metamorphosis, which it will accomplish providing that it is adequately stimulated by environmental factors.
The metamorphic larva stage consists essentially of the evagination of the echinoid rudiment. It is characterized by the execution of conspicuous and relatively abrupt physical changes that take place quite quickly, in about one hour, and during which the planktonic larva is transformed into a benthic juvenile. At that stage, the larva is settled on the substrate and is firmly attached to it by the primary podia of the rudiment. The ectodermal epithelium of its arms has started to collapse, making the spicules supporting the larval arms piercing through the epidermis. The larval mouth and anus have further closed, while in parallel, within the larva, the rudiment spines have lifted up thereby distending the vestibular wall and wide opening the vestibular pore. Following these movements, the rudiment has farther down accomplished and finalized its complete eversion, encapsulating the digestive tract and reaching the right side of the larval body. During this process, the genital plates and the associated pedicellariae and immature spines present on the right side of the larva have further completed the production of the aboral part of the adult body. At the end of metamorphosis, hence at the end of the metamorphic larva stage, the individual has thus become benthic, it is settled in the substrate, and it looks like an adult pentaradial sea urchin although it is smaller in size, deprived of a functional digestive system and sexually immature.
Biological process during which changes occur in biological and psychological domains to generate a sexually mature animal.
Period during which a young individual, posing as a small adult, grows but remains unable to reproduce.
The early juvenile is morphologically similar to both the late rudiment and a miniature sea urchin adult. Like the rudiment, it harbors five primary podia (or tube feet), five quartet of definitive spines, five pairs of immature spines located at the basis of the primary podia, 5 to 7 immature spines supported by the genital plates as well as 1 to 4 pedicellariae. Like the adult, it displays a pentarial symmetry and is settled on the substrate. An early juvenile is about 300 ÃƒÂ‚Ã‚Âµm in diameter. On its aboral side, it still exhibits some remaining larval rods and tissues, although these will soon disappear. In addition, the plates forming its endoskeleton are still rather light and porous making it looking relatively clear, although it bears lots of red-pigmented cells. However, the postlarva is still deprived of a mouth and an anus, hence of a functional digestive tract. The early juvenile is thus endotrophic, meaning that its growth and development solely relies on energy derived from internal sources. Furthermore, the early juvenile is sexually immature.
The late juvenile really looks like a small adult. The plates of its endoskeleton have by now densified providing it with a dark shell. In addition, it has finally developed a functional digestive tract. The digestive tract inherited from the larva has indeed by now undergone a complete reorganization, progressively bending within the perivisceral cavity to form two successive loops. The buccal plates and the aristotle lantern have further finished developing, creating a new mouth that has opened on the oral side at the center of the aristotle's lantern, while a new anus has also opened in the periproct, i.e. at the center of the five genital plates. The late juvenile can thus feed and starts growing in size, by grazing on the substrate. The late juvenile is exotrophic, meaning that its growth and development rely on energy derived from external sources. In addition, the primary podia have started to regress by that stage and will eventually disappear, while secondary podia have emerged and are functional, allowing the juvenile to move. Similarly, the immature spines have also started to be lost and be replaced by definitive spines. The genital plate CD has further differentiated into the madreporite and sphaeridia have formed. However, this individual is still sexually immature.
Period during which the animal reaches sexual maturity.
This stage corresponds to a fully formed pentaradial sea urchin that has reached sexual maturity. The gonads have developed within the perivisceral cavity and are connected to the outside by the genital pores pierced into the genital plates. The young adult has grown up to about several centimeters in diameter and is now producing gametes. Time after fertilization is unknown, between several months to one year depending on the sea urchin species and the rate and type of feeding.
The embryo is composed of about 800 cells and is surrounded by a fertilization envelope. The wall of the embryo is thinner and smoother than at previous stages. The vegetal plate has not formed. Many cells are ciliated but the embryo has not begun to rotate within the fertilization envelope. Note for euechinoid indirect developers: molecular labeling typically indicates the presence of 32 large micromere descendants and 4 small micromere descendants at this stage.
Stage when the vegetal plate is apparent but primary mesenchyme cells (PMCs) have not started to ingress. Embryos are motile due ciliary beating but have not completed hatching.
Biological entity that is either an individual member of a biological species or constitutes the structural organization of an individual member of a biological species.
Material anatomical entity that has inherent 3D shape and is generated by coordinated expression of the organism's own genome
A system that has as its parts distinct anatomical structures interconnected by anatomical structures at a lower level of granularity. Multicellular, connected anatomical structure that has multiple organs as parts and whose parts work together to achieve some shared function
A region of the whole organism without well-defined compartmental boundaries
Anatomical structure that is an individual member of a species and consists of one cell or more
Anatomical structure that is an individual member of a species and consists of more than one cell
Anatomical entity that comprises the animal in the early stages of growth and differentiation that are characterized by cleavage, the laying down of fundamental tissues, and the formation of primitive organs and organ systems
Anatomical system that has as its parts the organs devoted to the ingestion, digestion, and assimilation of food and the discharge of residual wastes.
The gastrointestinal tract that is being formed during embryonic development starting with the formation of the primitive gut tube (or archenteron)
Organ system responsible for the food uptake and processing in the larva
Anatomical system that processes ingested substances in the adult
Anatomical system that has as its parts the organs concerned with reproduction, i.e. the male and female gonads.
The sum of all the structures in the embryo that will develop into the larval nervous system
The sum of all the neural structures present in the larva
Internal support structure of an animal composed of mineralized tissue. It gives shape, support and protection to the body.
The water vascular system is a hydraulic system used by sea urchins for locomotion, food and waste transportation, and respiration. The system is composed of canals connecting numerous tube feet.
The hemal system contains the blood. It is composed of a complex network of vessels mainly located around the gut.
Anatomical region that corresponds to the upper half of the embryo, which later is composed of the mesomeres, and ultimately encompasses the presumptive ectoderm
Anatomical region that corresponds to the lower half of the embryo, which later is composed of the macromeres and the micromeres, and ultimately encompasses the endoderm and mesoderm
Cell component comprising the outermost layer of the animal region of the oocyte. It consists of a phospholipid bilayer and associated proteins
Cell component comprising the outermost layer of the vegetal region of the oocyte. It consists of a phospholipid bilayer and associated proteins
The apical region of the animal hemisphere
The apical most region of the vegetal hemisphere. Once cleavages have started the vegetal pole is characterized by the presence of the micromeres initially and then that of the small micromeres
Anatomical structure that has as its parts a maximally connected cell compartment surrounded by a plasma membrane
Anatomical structure that is part of a cell and that has a granularity level equal to that of a protein complex or higher.
Any of the organs or elements that are part of the digestive system
Any anatomical structure that is part of an embryo
Any anatomical structure that is part of a larva
Any anatomical structure that is part of a juvenile
Any anatomical structure that is part of an adult
A membrane-bounded organelle of in which chromosomes are housed and replicated. In most cells, it contains all of the cell's chromosomes except the organellar chromosomes, and is the site of RNA synthesis and processing. In some specialized cell types, RNA metabolism or DNA replication may be absent
The enlarged, fluid filled nucleus of a primary oocyte, the development of which is suspended in prophase I of the first meiotic division between embryohood and sexual maturity
The subequatorial accumulation of pigment granules (the so-called ÃƒÂ¢Ã¢Â‚Â¬Ã‹Âœpigment bandÃƒÂ¢Ã¢Â‚Â¬Ã¢Â„Â¢) in eggs or early stage embryos, which constitutes an unambiguous marker of animal-vegetal polarity
All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures
A structure that lies outside the plasma membrane and surrounds the egg. The fertilization envelope forms from the vitelline membrane after fertilization as a result of cortical granule release
A small cell formed by the meiotic division of an oocyte
The part of the late spermatid or spermatozoon that contains the nucleus and acrosome.
A microtubule-based flagellum (or cilium) that is part of a sperm, a mature male germ cell that develops from a spermatid
An organelle that develops over the anterior half of the head in the spermatozoa
A mature female gamet that has entered meiosis.
An undifferentiated cell produced by early cleavages of the fertilized egg (zygote)
Intermediate size blastomere forming the animal hemisphere of the cleaving embryo
Larger blastomere of the vegetal hemisphere of the cleaving embryo located below the equator
Small blastomere of the vegetal hemisphere of the cleaving embryo located at to the vegetal pole
presumptive skeletogenic mesenchyme cell
A progenitor cell of the nervous system that will develop into a neuron
animal pole domain neuronal progenitor cell
endoderm associated neuronal progenitor cell
Primary germ layer that is the outer of the embryo's three germ layers and gives rise to epidermis and neural tissue.
Group of four cells of equal size forming the animal hemisphere of an eight-cell stage embryo
Group of four cells of equal size forming the vegetal hemisphere of an eight-cell stage embryo
right ventrolateral triradiate spicule rudiment
left ventrolateral triradiate spicule rudiment
A triradiate or hexaradiate minute calcareous skeletal element that initiates most if not all skeletal structures found within the sea urchin embryo, larva and adult.
The embryonic tissue made up of loosely connected mesoderm cells that will produce all of the skeletal elements.
The subset of the embryonic mesoderm that will later give rise to the skeletogenic mesenchyme and embryonic skeleton.
Anatomical structure composed of skeletogenic mesenchyme cells that have fused to form a single syncytial network.
embryonic skeletogenic mesenchyme syncytium
subequatorial primary mesenchyme cell ring
subequatorial skeletogenic mesenchyme ring
Subpopulation of skeletogenic mesenchyme forming a chain on the oral (i.e. ventral) side of the embryo.
Subpopulation of skeletogenic mesenchyme forming a chain on the aboral (i.e. dorsal) side of the embryo.
Subpopulation of skeletogenic mesenchyme forming a cluster (i.e. a group of cells) in the ventrolateral region of the embryo.
right ventrolateral skeletogenic mesenchyme cluster
left ventrolateral skeletogenic mesenchyme cluster
Subpopulation of skeletogenic mesenchyme forming a chain on either side of the developing digestive tract, along the blastocoel wall and towards the animal pole.
lateral chain of skeletogenic mesenchyme
Subpopulation of skeletogenic mesenchyme forming a chain along the blastocoel wall towards the animal pole on the right side of the embryo.
right lateral chain of skeletogenic mesenchyme
Subpopulation of skeletogenic mesenchyme forming a chain along the blastocoel wall towards the animal pole on the left side of the embryo.
left lateral chain of skeletogenic mesenchyme
embryonic non-skeletogenic mesenchyme cell
a cell that contains red coloring matter
presumptive circumesophageal muscle cell
The mesenchyme cells that produce new skeletal elements (i.e., the posterodorsal rods, dorsal arch, and preoral rods) in the larva after feeding begins
The left lateral field is the lateral field located on the left side of the larva
Opening located in the left lateral field
The lateral field is located in the aboral ectoderm of the larva. It separates the anterior and posterior pairs of epaulettes
The right lateral field is the lateral field located on the right side of the larva
The mesenchyme cells that produce biomineralized elements (e.g., spines, test plates, and teeth) in the juvenile and adult.
A population of embryonic cells that share a common developmental fate or program of gene expression and comprising a region that lacks clear morphological boundaries
A multicellular organism that existence_ends_with a post-juvenile adult stage and existence_starts_with a post-juvenile adult stage.
A structure lying external to one or more cells, which provides structural support, biochemical or biomechanical cues for cells or tissues.
A cell that will develop into a neuron of the animal pole domain.
An ectodermal cell that will develop into a neuron.
A cell that will develop into a neuron of the ciliary band.
An endodermal cell that will develop into a neuron.
endoderm-ssociated neuronal progenitor cell
A neuron located near the base of an oral arm and outside the ciliary band.
A cell that will give rise to a postoral neuron.
A neuron that produces the synaptotagmin-B protein.
A neuron that produces the nitric oxide synthase protein.
A neuron that uses acetylcholine as a vesicular neurotransmitter.
A neuron that uses both acetylcholine and catecholamines as vesicular neurotransmitters.
One of two bilateral ganglia that arise in the oral ectoderm near the ciliary band.
The lateral ganglion that forms on the right side of the embryo.
The lateral ganglion that forms on the left side of the embryo.
The part of the blastula that will give rise to ventral ectoderm.
The part of the blastula that will give rise to dorsal ectoderm.
A dynamic terriritory within the prospective ectoderm of the early embryo, located at the anterior (animal) end of the embryo and shaped by Wnt signaling, that contains cells with neurogenic potential.
A dynamic territory within the prospective ectoderm of the early embryo, located between the anterior neuroectoderm and the endomesoderm.
The innermost part of the anterior neuroectoderm, immediately surrounding the animal pole.
A torus shaped region comprising the outer part of the anterior neuroectoderm.
A region of the ectoderm derived from the animal hemisphere (i.e., mesomere descendants) and located just above the equator on the ventral side of the embryo.
A region of the ectoderm derived from the animal hemisphere (i.e., mesomere descendants) and located between the central ventral ectoderm and the animal pole domain on the ventral side of the embryo.
A region of border ectoderm located on a lateral surface of the embryo.
A region of border ectoderm located on the ventral side of the embryo.
A region of border ectoderm located on the dorsal side of the embryo.
A region of ectoderm derived from the animal hemisphere and located laterally at the boundary between hte ventral and dorsal ectoderm; this region overlaps with part of the prospective ciliary band.
The animal lateral ectoderm on the right side of the embryo.
The animal lateral ectoderm on the left side of the embryo.
A portion of the ectoderm located at the tip of a postoral arm.
A portion of the ectoderm located at the tip of the right postoral arm.
A portion of the ectoderm located at the tip of the left postoral arm.
The cells that will give rise to the ciliary band.
An elongated extension of the embryo on the ventral side, supported by a simple or fenestrated skeletal rod and often covered in part by a ciliary band. Arms develop in bilaterally symmetrical pairs.
A type of arm that projects from the oral hood; forms after the postoral arms appear and prior to the appearance of the preoral and posterodorsal arms.
A type of arm that forms between the equator and the posterior pole, near the position of the skeletal rudiment; the first type of arm to appear.
A rod that forms by the branching or pronounced curving of the anterior tip of a dorsoventral connecting rod and that projects ventrally from the oral hood, supporting an anterolateral arm.
A rod that forms by the branching of the anonymous rod and projects ventrally, supporting a postoral arm.
A rod that initially forms as one of the three arms of the embryonic triradiate spicule rudiment; this rod extends toward the animal pole before branching or curving to form the anterolateral rod and, in some species, the recurrent rod.
A rod that initially forms as one of the three arms of the embryonic triradiate spicule rudiment; this rod projects toward the ventral midline and ceases growth early in development without branching.
The growing tip of the body rod as it extends dorsally.
The distal tip of the body rod that forms on the right side of the embryo.
The distal tip of the body rod that forms on the left side of the embryo..
A rod that forms from the branching of a dorsoventral transverse rod and extends dorsally.
The part of the embryonic presumptive mesoderm that will later give rise to the skeletogenic mesenchyme and embryonic skeleton.
presumptive embryonic skeletogenic mesoderm
A cluster of skeletogenic cell bodies that forms in the ventrolateral region of the subequatorial skeletogenic mesenchyme ring; one triradiate spicule rudiment will form in each of two ventrolateral clusters.
ventrolateral skeletogenic mesenchyme cluster
Embryonic cells tin the epithelial wall of the vegetal plate or the archenteron that will give rise to mesodermal derivatives other than skeleton.
presumptive embryonic non-skeletogenic mesoderm
The presumptive embryonic non-skeletogenic mesoderm on the ventral side of the embryo.
ventral presumptive embryonic non-skeletogenic mesoderm
The presumptive embryonic non-skeletogenic mesoderm on the dorsal side of the embryo.
dorsal presumptive embryonic non-skeletogenic mesoderm
A cell that will give rise to a muscle cell.
The inner, extracellular space between blastomeres of the cleavage stage embryo that will gradually expand and form the blastocoel.
A cell that is part of the pyloric sphincter.
A cell that is part of the cardiac sphincter.
A cell that is part of the anal sphincter.
A strand of mesenchyme cells that extends from the left coelom to the ectoderm and that will give rise to the primary pore canal.
An evagination of the midgut that will contribute to the coelom.
In species with a posterior enterocoel, the left coelomic pouch that evaginates from the unpaired coelomic pouch at the anterior end of the archenteron.
In species with a posterior enterocoel, the right coelomic pouch that evaginates from the unpaired coelomic pouch at the anterior end of the archenteron.
In species with two separate ciliary bands, a ciliary band that surrounds the anterior-ventral end of the embryo, anterior to the mouth.
In species with two separate ciliary bands, a ciliary band that surrounds the posterior-dorsal end of the embryo, posterior to the mouth.
An anatomical structure that is a subdivision of a tissue, a germ layer, or an organ of the whole organism but with well-defined morphological boundaries.
A diploid cell produced by the fusion of a male and a female gamete at fertilization. It constitutes the first stage of the embryogenesis life cycle phase.
A multicellular organism at an early stage of development characterized by cleavage. It includes all forms of the cleavage period during the embryogenesis life cycle phase (i.e., from first cleavage to before the formation of the blastula).
A multicellular organism at an early stage of development corresponding to a hollow, spherical, multicellular, monolayered embryo with a hollow cavity (the blastocoel) in the center. It includes all forms of the blastula period during the embryogenesis life cycle phase.
A multicellular organism at an early stage of development characterized by morphogenetic movements. It includes all forms of the gastrula period during the embryogenesis life cycle phase.
A multicellular organism the existence of which starts at fertilization and ends with metamorphosis. It includes all forms during the embryogenesis and larval development life cycle phases.
A multicellular organism the existence of which starts upon the opening of the mouth and ends with death. It includes all forms during the larval development and adulthood life cycle phases.
A multicellular organism the existence of which starts with gamete production and ends with death.
A portion of an embryo (or a population of embryonic cells) that is characterized by a common developmental fate or a common gene expression program but lacks any clear morphological boundaries.
A portion of a larva (or a population of larval cells) that is characterized by a common developmental fate or a common gene expression program but lacks any clear morphological boundaries.
A population of cells that, throughout the embryogenesis and larval development life cycle phases, is characterized by a common developmental fate or a common gene expression program but lacks any clear morphological boundaries.
A multicellular anatomical structure made of several tissues, performing a specific function or group of functions.
A tissue that is present in a pre-metamorphic organism.
An anatomical structure that is part of a pre-metamorphic organism.
The immune system of a pre-metamorphic organism.
An anatomical reproductive system that is present in a female multicellular organism.
An anatomical reproductive system that is present in a male multicellular organism.
The neurons and glial cells constituting the nervous system of a pre-metamorphic organism.
The endoskeleton of a pre-metamorphic organism.
A specialized form of connective tissue in which the extracellular matrix is mineralized and that functions in mechanical and structural support.
A cell tier present in the animal hemisphere of an embryo.
A cell tier present in the vegetal hemisphere of an embryo.
The portion of a cell bearing surface projections such as axons, filopodia, dendrites, cilia, or flagella that includes the nucleus, but excludes all cell projections.
A cell that is within the developmental lineage of gametes and is able to pass along its genetic material to offspring.
A germ cell that supports female gamete production.
A germ cell that supports male gamete production.
The reproductive haploid, mature sexual reproductive cell of a multicellular organism.
An immature oocyte that is diploid and has not completed female meiosis I.
An immature oocyte that is haploid but has not completed female meiosis II.
An euploid male germ cell of an early stage of spermatogenesis. It is morphologically unlike spermatocytes and spermatids.
A male germ cell that develops from spermatogonia.
A male germ cell that develops from spermatocytes.
An intracellular anatomical structure in which the male chromosomes are housed.
An intracellular anatomical structure in which the female chromosomes are housed.
Any constituent part of a cell that is either an immaterial entity or a material entity with granularity above the level of a protein complex but below that of an anatomical structure.
A component of a cell contained within (but not including) the plasma membrane. It includes as examples the nucleus, mitochondria, vesicles, and the cytoskeleton.
A cell junction that forms a connection between two or more cells of a multicellular organism.
A strong cell-cell junction usually found in tissue that experience intense mechanical stress.
A cell-cell junction that forms a continuous band around each cell in an epithelium.
A cell-cell junction composed of the epithelial cadherin-catenin complex.
The part of the cytoskeleton composed of microtubules and associated proteins.
A component of a cytoskeleton consisting of a homo or heteropolymeric fiber constructed from an indeterminate number of protein subunits.
The either end of a spindle, from where the spindle microtubules emanate.
The middle region of an oocyte or a zygote, which comprises the most basal portion of the animal and vegetal hemispheres.
A multisubunit complex that is located on chromosomes and provides an attachment point for the spindle microtubules.
A cilium that develops on the apical surface of a cell.
A cilium of short size exhibiting motility thanks to the molecular motors it contains. In echinoderms, short motile cilia are encountered on the outer surface of the developing embryo as well as in the developing and developed digestive tract of embryos and larvae.
A cilium of long size that does not contain molecular motors and as such does not exhibit any beating movement. In some echinoderms, long immotile cilia are found, when present, at the animal pole of embryos and constitute the apical tuft.
A sheet-like cellular projection that is supported by an ordered network of actin filaments and that is involved in cellular motility and syncytium formation.
A small, dense body present in the nucleus of cells and that is rich in RNA and protein, not bounded by a limiting membrane, and not seen during mitosis.
A structure composed of a very long molecule of DNA and associated proteins (e.g. histones) that carries hereditary information.
An undifferentiated cell part of the animal hemisphere of an embryo.
An undifferentiated cell part of the vegetal hemisphere of an embryo.
A cell derived from a macromere through cell division.
The inner, extracellular space between blastomeres of the cleavage stage embryos that will gradually expand and form the blastocoel.
The most apical region of the blastocoel.
The region of the blastocoel comprised in the middle region of the embryo, below the blastocoel roof.
An epithelium derived from ectoderm and constituting the outermost protective layer of an embryo, a larva, or an adult.
A tissue that consists of one or more layers of epithelial cells connected to each other by cell junctions and which is underlain by a basal lamina.
The ectoderm that is specifically present in an embryo
The ectoderm that is specifically present in a larva.
The ectoderm that is specifically present in an embryo and a larva but not in an adult.
The ectoderm that specifically derives from cells of the veg1 tier.
The ectoderm that is part of the animal ectoderm but located below the apical pole domain ectoderm.
A thickened region at the animal hemisphere, located at the animal pole, and that contains developing neurons and cells with elongated cilia.
The ectoderm that is part of the animal ectoderm and is specifically restricted to the apical pole domain.
The portion of the presumptive ectoderm that is located on the oral side of the embryo (which will later generate the ventral side of the larva).
The portion of the embryonic ectoderm that is located on the oral side of the embryo and will give rise to ventral ectoderm of the larva.
The portion of the presumptive ectoderm that is located on the aboral side of the embryo (which will later generate the dorsal side of the larva).
The portion of the embryonic ectoderm that is located on the aboral side of the embryo and will give rise to dorsal ectoderm of the larva.
The portion of the border ectoderm that is located on the oral side of the embryo.
The portion of the border ectoderm that is located on the aboral side of the embryo.
The portion of the presumptive oral ectoderm where the stomodeum will form.
The portion of the oral ectoderm where the stomodeum forms.
The portion of the ectoderm where neurons form.
An ectodermal progenitor cell from the animal pole domain that will develop into a neuron.
A neuronal progenitor cell present in the epidermis of a postoral arm.
A neuronal progenitor cell present in the epidermis of the oral hood.
A neuron that is located in the postoral arm ectoderm outside the ciliary band.
A neuron that is located in the oral hood.
A neuron of which transmission is mediated by nitric oxide.
The long process of a neuron that conducts nerve impulses, usually away from the neural cell body.
The portion of a neuron that includes the nucleus, but excludes cell projections such as axons.
A neural structure that develops from the apical pole domain, above the mouth, and contains neurons.
A specific embryonic or larval ectodermal territory located on the oral side and that will give rise to the oral hood ciliary band.
A cell that composes the oral hood ciliary band.
The portion of the ciliary band that covers the arm buds.
The portion of the arm ciliary band that covers the arm distal tip.
The portion of the arm ciliary band that covers the arm proximal tip.
The portion of the arm ciliary band that covers the region of the arm between the distal and proximal tips.
The portion of the presumptive ciliary band that overlaps with the animal pole domain.
The portion of the presumptive ciliary band located close to the vegetal pole.
The portion of the presumptive ciliary located between the animal and the vegetal presumptive ciliary bands.
In species with two separate ciliary bands, a specific embryonic territory that will develop into the preoral ciliary band.
In species with two separate ciliary bands, a specific embryonic territory that will develop into the postoral ciliary band.
A specific ectodermal territory located on the oral side of the embryo or the larva and that will give rise to the oral hood.
An embryonic region that will develop into an arm.
The distal extremity of a larval arm, i.e. the further away from the larval body
The proximal extremity of a larval arm, i.e. the closest to the larval body
The portion of a larval arm comprised between the distal and proximal tips of the arm.
The thickened ectodermal region that outlines the arm bud.
The ectodermal (or epidermal) portion of the arm skin and that does not include the ciliary band.
The ectodermal (or epidermal) that covers the distal arm tip and does not include the ciliary band.
The ectodermal (or epidermal) that covers the proximal arm tip and does not include the ciliary band.
The ectodermal (or epidermal) that covers the portion of the arm located between the distal and proximal tips and that does not include the ciliary band.
A skeletogenic mesenchyme cell present in the arm bud and that will contribute to the development of a skeletal rod.
The distal tip of a skeletal rod, i.e. the further away from its initiation site.
The proximal tip of a skeletal rod, i.e. the closest to its initiation site.
The portion of a skeletal rod comprised between the distal and proximal tips of the rod.
The distal tip of an arm skeletal rod, i.e. the further away from its initiation site and the larval body.
The proximal tip of an arm skeletal rod, i.e. the closest to its initiation site and the larval body.
The portion of an arm skeletal rod comprised between the distal and proximal tips of the rod.
A skeletogenic mesenchyme cell part of a skeletal rod.
skeletal rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a skeletal rod.
skeletal rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a skeletal rod.
skeletal rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell part of the region of a skeletal rod comprised between the distal and proximal tips of the rod.
skeletal rod middle portion skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell part of an arm skeletal rod.
arm skeletal rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of an arm skeletal rod.
arm skeletal rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of an arm skeletal rod.
arm skeletal rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell part of the region of an arm skeletal rod comprised between the distal and proximal tips of the rod.
arm skeletal rod middle portion skeletogenic mesenchyme cell
An arm bud that will develop into a postoral arm.
The arm bud on the right side of the embryo that will develop into a postoral arm.
The arm bud on the left side of the embryo that will develop into a postoral arm.
The proximal tip of a right postoral arm.
The proximal tip of a left postoral arm.
The middle region of a postoral arm comprised between the distal and proximal tip of the arm.
The middle region of a right postoral arm.
The middle region of a left postoral arm.
The portion of the ectoderm that outlines a postoral arm bud.
The portion of the ectoderm that outlines a postoral arm bud on the right side of the embryo.
The portion of the ectoderm that outlines a postoral arm bud on the left side of the embryo.
The ectoderm (or epidermis) that covers a postoral arm but does not include the ciliary band.
The ectoderm (or epidermis) that covers a right postoral arm but does not include the ciliary band.
The ectoderm (or epidermis) that covers a left postoral arm but does not include the ciliary band.
The portion of a postoral arm ectoderm located at the distal tip of the arm.
The postoral arm distal tip ectoderm part of a right postoral arm.
The postoral arm distal tip ectoderm part of a left postoral arm.
The portion of a postoral arm ectoderm located at the proximal tip of the arm.
The postoral arm proximal tip ectoderm part of a right postoral arm.
right postoral arm proximal tip ectoderm
The postoral arm proximal tip ectoderm part of a left postoral arm.
The portion of a postoral arm ectoderm located between the distal and proximal tips of the arm.
The postoral arm middle portion ectoderm part of a right postoral arm.
right postoral arm middle portion ectoderm
The postoral arm middle portion ectoderm part of a left postoral arm.
left postoral arm middle portion ectoderm
The proximal tip of a right postoral rod.
The proximal tip of a left postoral rod.
The middle region of a postoral rod comprised between the distal and proximal tip of the rod.
The middle region of a right postoral rod.
The middle region of a left postoral rod.
A skeletogenic mesenchyme cell part of a postoral rod.
postoral rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell part of a right postoral rod.
right postoral rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell part of a left postoral rod.
left postoral rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a postoral rod.
postoral rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a right postoral rod.
right postoral rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a left postoral rod.
left postoral rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a postoral rod.
postoral rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a right postoral rod.
right postoral rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a left postoral rod.
left postoral rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of a postoral rod, comprised between the distal and proximal tips of the rod.
postoral rod middle portion skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of a right postoral rod.
right postoral rod middle portion skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of a left postoral rod.
left postoral rod middle portion skeletogenic mesenchyme cell
The distal tip of a right anonymous rod.
The proximal tip of a right anonymous rod.
The proximal tip of a left anonymous rod.
The middle region of an anonymous rod comprised between the distal and proximal tip of the rod.
The middle region of a right anonymous rod.
The middle region of a left anonymous rod.
A skeletogenic mesenchyme cell part of an anonymous rod.
anonymous rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell part of a right anonymous rod.
right anonymous rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell part of a left anonymous rod.
left anonymous rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of an anonymous rod.
anonymous rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a right anonymous rod.
right anonymous rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a left anonymous rod.
left anonymous rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of an anonymous rod.
anonymous rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a right anonymous rod.
right anonymous rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a left anonymous rod.
left anonymous rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of an anonymous rod, comprised between the distal and proximal tips of the rod.
anonymous rod middle portion skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of a right anonymous rod.
right anonymous rod middle portion skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of a left anonymous rod.
left anonymous rod middle portion skeletogenic mesenchyme cell
The distal tip of an anterolateral rod, i.e. away from its connection with the dorsoventral connecting rod.
The distal tip of a right anterolateral rod.
The distal tip of a left anterolateral rod.
The proximal tip of an anterolateral rod, i.e. in connection with the dorsoventral connecting rod.
The proximal tip of a right anterolateral rod.
The proximal tip of a left anterolateral rod.
The middle portion of an anterolateral rod, i.e., comprised between the distal and proximal tips of the rod.
The middle portion of a right anterolateral rod.
The middle portion of a left anterolateral rod.
A skeletogenic mesenchyme cell part of an anterolateral rod.
anterolateral rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell part of a right anterolateral rod.
right anterolateral rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell part of a left anterolateral rod.
left anterolateral rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of an anterolateral rod.
anterolateral rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a right anterolateral rod.
right anterolateral rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a left anterolateral rod.
left anterolateral rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of an anterolateral rod.
anterolateral rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a right anterolateral rod.
right anterolateral rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a left anterolateral rod.
left anterolateral rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of an anterolateral rod, comprised between the distal and proximal tips of the rod.
anterolateral rod middle portion skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of a right anterolateral rod.
right anterolateral rod middle portion skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of a left anterolateral rod.
left anterolateral rod middle portion skeletogenic mesenchyme cell
The portion of a dorsoventral connecting rod that bends (or branches) to give rise to the anterolateral rod and in some echinoid species to the recurrent rod.
anterior tip of dorsoventral connecting rod
anterior end of dorsoventral connecting rod
The animal tip of a right dorsoventral connecting rod.
right dorsoventral connecting rod animal tip
The animal tip of a left dorsoventral connecting rod.
left dorsoventral connecting rod animal tip
The distal tip of a dorsoventral connecting rod, i.e. in connection with the anterolateral rod and in some echinoid species the recurrent rod.
The distal tip of a right dorsoventral connecting rod.
right dorsoventral connecting rod distal tip
The distal tip of a left dorsoventral connecting rod.
left dorsoventral connecting rod distal tip
The proximal tip of a dorsoventral connecting rod, i.e. in connection with the anonymous and ventral transverse rods.
dorsoventral connecting rod proximal tip
The proximal tip of a right dorsoventral connecting rod.
right dorsoventral connecting rod proximal tip
The proximal tip of a left dorsoventral connecting rod.
left dorsoventral connecting rod proximal tip
The middle portion of a dorsoventral connecting rod, i.e., comprised between the distal and proximal tips of the rod.
dorsoventral connecting rod middle portion
The middle portion of a right dorsoventral connecting rod.
right dorsoventral connecting rod middle portion
The middle portion of a left dorsoventral connecting rod.
left dorsoventral connecting rod middle portion
A skeletogenic mesenchyme cell part of a dorsoventral connecting rod.
dorsoventral connecting rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell part of a right dorsoventral connecting rod.
right dorsoventral connecting rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell part of a left dorsoventral connecting rod.
left dorsoventral connecting rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell part of the bended portion of a dorsoventral connecting rod, before this portion elongates and becomes an anterolateral rod or in some echinoid species branches into a anterolateral and a recurrent rods.
dorsoventral connecting rod animal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the animal tip of a right dorsoventral connecting rod.
right dorsoventral connecting rod animal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the animal tip of a left dorsoventral connecting rod.
left dorsoventral connecting rod animal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a dorsoventral connecting rod, before its bended portion.
dorsoventral connecting rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a right dorsoventral connecting rod.
right dorsoventral connecting rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a left dorsoventral connecting rod.
left dorsoventral connecting rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a dorsoventral connecting rod, in the vicinity of an anonymous and ventral transverse rod.
dorsoventral connecting rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a right dorsoventral connecting rod.
right dorsoventral connecting rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a left dorsoventral connecting rod.
left dorsoventral connecting rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of a dorsoventral connecting rod, comprised between the distal and proximal tips of the rod.
dorsoventral connecting rod middle portion skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of a right dorsoventral connecting rod.
right dorsoventral connecting rod middle portion skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of a left dorsoventral connecting rod.
left dorsoventral connecting rod middle portion skeletogenic mesenchyme cell
The distal tip of a ventral transverse rod, i.e. away from the connection with the dorsoventral connecting and anonymous rods.
The distal tip of a right ventral transverse rod.
The distal tip of a left ventral transverse rod.
The proximal tip of a ventral transverse rod, i.e. in connection with the dorsoventral connecting and anonymous rods.
The proximal tip of a right ventral transverse rod.
right ventral transverse rod proximal tip
The proximal tip of a left ventral transverse rod.
left ventral transverse rod proximal tip
The middle portion of a ventral transverse rod, i.e., comprised between the distal and proximal tips of the rod.
The middle portion of a right ventral transverse rod.
right ventral transverse rod middle portion
The middle portion of a left ventral transverse rod.
left ventral transverse rod middle portion
A skeletogenic mesenchyme cell part of a ventral transverse rod.
ventral transverse rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell part of a right ventral transverse rod.
right ventral transverse rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell part of a left ventral transverse rod.
left ventral transverse rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a ventral transverse rod.
ventral transverse rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a right ventral transverse rod.
right ventral transverse rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a left ventral transverse rod.
left ventral transverse rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a ventral transverse rod.
ventral transverse rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a right ventral transverse rod.
right ventral transverse rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a left ventral transverse rod.
left ventral transverse rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of a ventral transverse rod, comprised between the distal and proximal tips of the rod.
ventral transverse rod middle portion skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of a right ventral transverse rod.
right ventral transverse rod middle portion skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of a left ventral transverse rod.
left ventral transverse rod middle portion skeletogenic mesenchyme cell
The growing tip of a body rod as it extends dorsally away from an anonymous rod.
The proximal tip of a body rod, i.e. in connection with an anonymous rod.
The middle portion of a body rod, i.e., comprised between the distal and proximal tips of the rod.
A skeletogenic mesenchyme cell part of a body rod.
A skeletogenic mesenchyme cell part of a right body rod.
right body rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell part of a left body rod.
left body rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a body rod.
body rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a right body rod.
right body rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a left body rod.
left body rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a body rod.
body rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a right body rod.
right body rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a left body rod.
left body rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of a body rod, comprised between the distal and proximal tips of the rod.
body rod middle portion skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of a right body rod.
right body rod middle portion skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of a left body rod.
left body rod middle portion skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell part of a scheitel.
The distal tip of a recurrent rod, i.e. in connection with a dorsoventral connecting rod.
The distal tip of a right recurrent rod.
The proximal tip of a recurrent rod, i.e. away from a dorsoventral connecting rod.
The proximal tip of a right recurrent rod.
The proximal tip of a left recurrent rod.
The middle portion of a recurrent rod, i.e., comprised between the distal and proximal tips of the rod.
The middle portion of a right recurrent rod.
The middle portion of a left recurrent rod.
A skeletogenic mesenchyme cell part of a recurrent rod.
recurrent rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell part of a right recurrent rod.
right recurrent rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell part of a left recurrent rod.
left recurrent rod skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a recurrent rod.
recurrent rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a right recurrent rod.
right recurrent rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the distal tip of a left recurrent rod.
left recurrent rod distal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a recurrent rod.
recurrent rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a right recurrent rod.
right recurrent rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the proximal tip of a left recurrent rod.
left recurrent rod proximal tip skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of a recurrent rod, comprised between the distal and proximal tips of the rod.
recurrent rod middle portion skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of a right recurrent rod.
right recurrent rod middle portion skeletogenic mesenchyme cell
A skeletogenic mesenchyme cell composing the middle portion of a left recurrent rod.
left recurrent rod middle portion skeletogenic mesenchyme cell
The presumptive endoderm that develops specifically from the cells of the vegetal tier 1.
The presumptive endoderm that develops specifically from the cells of the vegetal tier 2.
The endoderm that is specifically present in an embryo.
The endoderm that is specifically present in a larva.
The endoderm that is specifically present in an embryo post-gastrulation and a larva but not in an adult.
The anterior territory of the archenteron.
The layer of cells that form the archenteron, but at the level of its anterior tip and that of the blastopore.
The middle portion of the hindgut, between its anterior and posterior portions.
The middle portion of the midgut, between its anterior and posterior portions.
The middle portion of the foregut, between its anterior and posterior portions.
The anterior end of the animal digestive tract that connects the mouth to the stomach.
The central region of the animal digestive tract that serves as a digestive organ.
The posterior region of the animal digestive tract that extends from the stomach to the anus.
The outpocketing of the mesoderm constituting the tip of the archenteron and forming a bilobed bag (or pouch) lying on the top of the archenteron roof.
A mesodermally lined pouch (or pocket) lying between the anterior tip of the archenteron and the outer body wall.
A narrowing (or shrinking) within a tissue or organ to delineate different regions with different fates.
A constriction taking place at the level of a coelom. It can either separate the coelom from the archenteron or lead to the compartmentalization of the coelom into distinct regions.
In species with a posterior enterocoel, the anterior coelomic pouch is the one that develops from the unpaired coelomic evaginations at the tip of the archenteron.
An epidermal tissue present in the larva.
The epidermal tissue of the larva that surrounds the mouth.
The epidermal tissue of the larva that is on the side opposite to the mouth.
A cell that has undergone epithelial to mesenchymal transition and is capable of migration.
The region of the early embryo that will develop into skeletogenic mesoderm.
The subset of the mesoderm germ layer that will exclusively give rise to the endoskeleton.
A cell that has the potential of developing into a skeletogenic mesenchyme cell (or skeletal cell).
The portion of the mesenchyme tissue that constitutes the endoskeleton.
A cell that after having undergone epithelial to mesenchymal transition participates in constituting the endoskeleton.
A filopodial cable that participates in the establishment of a syncytium.
A straight, syncitial network that either links the two ventrolateral skeletogenic mesenchyme clusters within the subequatorial skeletogenic mesenchyme ring or extends from the ventrolateral skeletogenic mesenchyme clusters towards the animal pole domain.
The chain of skeletogenic mesenchyme cell that within the subequatorial skeletogenic mesenchyme ring links the two ventrolateral skeletogenic mesenchyme clusters on the oral side of the embryo. The ventral transverse rods will be deposited along this cellular strand.
oral chain of skeletogenic mesenchyme cell
The chain of skeletogenic mesenchyme cell that within the subequatorial skeletogenic mesenchyme ring links the two ventrolateral skeletogenic mesenchyme clusters on the aboral side of the embryo. The body rods will be deposited along this cellular strand.
aboral chain of skeletogenic mesenchyme cell
A cluster of skeletogenic mesenchyme cells that aggregates before any calcification event whether in the embryo, the larva, or the adult.
A chain of skeletogenic mesenchyme cell that extends from a ventrolateral cluster toward the animal pole. A dorsoventral connecting rod will be deposited along this cellular strand.
lateral chain of skeletogenic mesenchyme cell
The lateral chain that forms on the right side of the embryo from the right ventrolateral cluster.
right lateral chain of skeletogenic mesenchyme cell
The lateral chain that forms on the left side of the embryo from the left ventrolateral cluster.
left lateral chain of skeletogenic mesenchyme cell
A skeletal, calcified structure composed of three elongated skeletal rods.
A spicule granule that forms within a ventrolateral cluster of skeletogenic mesenchyme cells.
A ventrolateral spicule granule that forms on the right side of the embryo.
A ventrolateral spicule granule that forms on the left side of the embryo.
A triradiate spicule rudiment that forms within a ventrolateral cluster of skeletogenic mesenchyme cells.
ventrolateral triradiate spicule rudiment
An embryonic, larval or adult region that will develop into non-skeletogenic mesoderm and/or mesenchyme derivatives.
The subset of the mesoderm germ layer that will give rise to all mesoderm tissue derivatives but the endoskeleton; e.g. muscles, coeloms, pigment cells, blastocoelar cells.
A cell part of the mesoderm germ layer subset that will give rise to all mesoderm tissue derivatives but the endoskeleton; e.g. muscles, coeloms, pigment cells, blastocoelar cells.
All mesenchyme present in the embryo, larva, or adult but that does not constitute the endoskeleton.
A mesenchymal cell that participates in the elaboration of all mesenchyme derivatives but the endoskeleton; e.g. pigment cells, blastocoelar cells.
The presumptive embryonic non-skeletogenic mesoderm that derives from the vegetal 2 tier cells and not from the small micromere descendants.
vegetal tier 2 non-skeletogenic mesoderm
In echinoderms with no embryonic endoskeleton, all embryonic cells that have undergone an epithelial-to-mesenchymal transition and will participate in the elaboration of non-skeletogenic mesoderm derivatives; e.g. pigment cells, blastocoelar cells.
In echinoderms with no larval endoskeleton, all larval mesenchyme cells that participate in the elaboration of non-skeletogenic mesoderm derivatives; e.g. pigment cells, blastocoelar cells.
The presumptive embryonic non-skeletogenic mesoderm that in the vegetal plate is on the oral side of the embryo.
oral presumptive embryonic non-skeletogenic mesoderm
The presumptive embryonic non-skeletogenic mesoderm that in the vegetal plate is on the aboral side of the embryo.
aboral presumptive embryonic non-skeletogenic mesoderm
A cell of the immune system that is involved in protecting the body against infectious disease and foreign invaders.
The subset of the filopodial cells that are phagocytic and express the immune effector gene 185/333.
An initial constriction within the archenteron marking where a sphincter will form.
The initial constriction within the archenteron that will develop into the pyloric sphincter and separates the midgut and hindgut.
The initial constriction within the archenteron that will develop into the cardiac sphincter and separates the foregut and the midgut.
The initial constriction at the posterior end of the archenteron (i.e. at the level of the blastopore) that will develop into the anal sphincter.
A cell that is part of a pyloric sphincter.
A cell that is part of a cardiac sphincter.
A cell that is part of an anal sphincter.