[Detection of transcription factor Xvent-2 in early development of Xenopus laevis]

The transcription factor Xvent-2 is considered to appear in the embryos of Xenopus after starting of activity of zygote genome, at midblastula stage. But nobody has detected this protein immunologically. All researchers deal with mRNA only. We first obtained antiserum to recombinant His-Xvent-2 and showed that the transcription factor Xvent-2 was present in eggs and embryos of Xenopus laevis from the cleavage up to the beginning of spontaneous motions (stage 26). On the contrary, Xvent-2 mRNA could not be detected in embryos before midblastula transition. The content of this mRNA grows up to maximum at the stages 15-16 and then lowers. The content of the Xvent-2 protein is constant, approximately 150 pg per an embryo. The conclusion was made that Xvent-2 was maternally provided and stored in eggs. The regulation of its synthesis in the embryos was independent on the corresponding mRNA quantity.