[A comparison of the inducing ability from the superficial layer of the yolk platelet coats and the microsomal fraction of cleavage, gastrula and neurula stages of Xenopus laevis].

Deuterencephalic and spinocaudal inducing activity is extractable from the yolk platelet coats and the microsomal fraction of cleavage, gastrula and neurula stages ofXenopus laevis.Extracts of both cell fractions from the gastrula and neurula cause a significantly stronger deuterencephalic and spinocaudal reaction than those from cleavage stages, when tested anTriturus alpestus ectoderm.