All components required for the eventual activation of muscle-specific actin genes are localized in the subequatorial region of an uncleaved amphibian egg.

Authors:
Publisher website
Google Scholar
Abstract
Fertilized Xenopus eggs were ligated with a hair loop into separate fragments before the 1st cleavage. The plane of the ligation was varied in relation to the animal-vegetal and dorso-ventral axes. The fragments that contained a nucleus were cultured for 24 h until controls reached the neurula stage; they were then analyzed by S1 nuclease protection for their content of muscle-specific actin mRNA, using a gene-specific probe. All egg components required for the eventual activation of these actin genes are localized, already at the 1-cell stage, in a region below the equator and mostly on the dorsal (grey crescent) side. This material subsequently occupies the equivalent position in 8-cell and 32-cell embryos. Mesoderm (including muscle) formation in Amphibia depends both on cytoplasmic substances already localized in the egg as well as on inductive cell interactions during cleavage.

This publication has 14 references indexed in Scilit: