Evolutionary dissociation between cleavage, cell lineage and embryonic axes in sea urchin embryos.
Development
; 114(4): 931-8, 1992 Apr.
Article
en En
| MEDLINE
| ID: mdl-1618154
Using vital dye staining and the microinjection of fluorescent cell lineage-autonomous tracers, the relationship between the first cleavage plane and the prospective larval dorsoventral axis was examined in several sea urchin species, including: Strongylocentrotus purpuratus, S. droebachiensis, Lytechinus pictus, Clypeaster rosaceus, Heliocidaris tuberculata and H. erythrogramma. The results indicate that there is no single relationship between the early cleavage pattern and the dorsoventral axis for all sea urchins; however, specific relationships exist for individual species. In S. purpuratus the first cleavage plane occurs at an angle 45 degrees clockwise with respect to the prospective dorsoventral axis in most cases, as viewed from the animal pole. On the other hand, in S. droebachiensis, L. pictus and H. tuberculata, the first cleavage plane generally corresponds with the plane of bilateral symmetry. There does not appear to be a predominant relationship between the first cleavage plane and the dorsoventral axis in C. rosaceus. In the direct-developing sea urchin H. erythrogramma the first cleavage plane bisects the dorsoventral axis through the frontal plane. Clearly, evolutionary differences have arisen in the relationship between cleavage pattern and developmental axes. Therefore, the mechanism of cell determination is not necessarily tied to any particular pattern of cell cleavage, but to an underlying framework of axial systems resident within sea urchin eggs and embryos.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Erizos de Mar
/
Fase de Segmentación del Huevo
/
Evolución Biológica
Límite:
Animals
Idioma:
En
Revista:
Development
Asunto de la revista:
BIOLOGIA
/
EMBRIOLOGIA
Año:
1992
Tipo del documento:
Article
Pais de publicación:
Reino Unido