Inducing effects of the grey crescent region of early developmental stages of ambystoma mexicanum.

Parts of the grey crescent region of 1-2 cell, 8 cell and morula stages ofAmbystoma mexicanum were combined with presumptive gastrula ectoderm of the same species (sandwich method).Grey crescent material of the early cleavage stages induced neural tissues at a very low rate (6%-7%).From the morula stage onwards, the inducing ability of the grey crescent area increased and led to the formation of mesodermal as well as neural organs. The implanted area did not participate in the organ formations.