Abstract:
In this study we have compared the in vitrodifferentiation potential of epiblast tissue from mouse and rat embryos.Epiblasts were isolated from egg cylinder stage embryos by microdissection andplaced in culture. Rat cultures were distinguished by the copious productionof parietal endoderm cells. Mouse epiblasts, in contrast, did not produceparietal endoderm. This difference in capacity to regenerate extraembryonicendoderm marks a surprising distinction in development of the pluripotentiallineage between these two closely related rodents.