The c-mos proto-oncogene product is a cytostatic factor responsible for meiotic arrest in vertebrate eggs

  • Nature. 1989 Nov 30;342(6249):512-8. doi: 10.1038/342512a0.
N Sagata  1 ,  N Watanabe ,  G F Vande Woude ,  Y Ikawa
Affiliations
  • 1. Tsukuba Science Center (RIKEN), Ibaraki, Japan.
PMID: 2531292 DOI: 10.1038/342512a0
Abstract

The c-mos proto-oncogene product, pp39mos, is present in unfertilized Xenopus eggs, and disappears on fertilization. Microinjection of synthetic mos RNA into two-cell embryos induces cleavage arrest at metaphase. By contrast, egg cytosol extracts, when immunodepleted of endogenous pp39mos, lose their cleavage-arresting activity in injected embryos. These results demonstrate that Mos protein is the cytostatic factor CSF, long known as an endogenous meiotic inhibitor in vertebrate eggs.