title: Cell proliferation in the ectoderm of the Xenopus embryo: development of substratum requirements for cytokinesis.
abstract: The requirements for cell division in ectodermal blastomeres of the early Xenopus embryo were studied. Isolated blastomeres divide autonomously on nonadhesive agar in a simple salt solution up to the midblastula stage. After the midblastula transition, cell-cell contact is required for blastomere division. In isolated blastomeres of that stage, cytokinesis fails, but nuclear division continues normally for some time. Cell-cell contact as a prerequisite for blastomere division can be replaced by culturing blastomeres on an appropriate substratum. Clonal growth of isolated blastomeres is supported by a variety of protein substrata, indicating rather unspecific substratum requirements. Different substrata which do not support blastomere division can affect different steps in cytokinesis.
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000166:cytology; D002448:Cell Adhesion; D002455:Cell Division; D002467:Cell Nucleus / Q000502:physiology; D003470:Culture Media; D004247:DNA / Q000096:biosynthesis; D004475:Ectoderm / Q000166:cytology*; D004625:Embryo, Nonmammalian / Q000166:cytology; D005109:Extracellular Matrix / Q000502:physiology; D014982:Xenopus laevis / Q000196:embryology*
chemical_list: D003470:Culture Media; D004247:DNA