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

The transcription factor Xvent-2 is thought to appear in Xenopus embryos after activation of the zygote genome in late blastula. This conclusion is based on detection of the Xvent-2 mRNA in embryos. Recombinant Xvent-2 and a specific antiserum were obtained and used to study Xvent-2 content at various stages of early development of X. laevis. Xvent-2 was detected in eggs and embryos from cleavage to the beginning of spontaneous motions (stage 26). As in other studies, the Xvent-2 mRNA was undetectable in embryos before the midblastula transition. The content of this mRNA grew, reached its maximum at stages 15–16, and then decreased. The content of the Xvent-2 protein remained constant, approximately 150 pg per embryo. The conclusions were made that Xvent-2 was maternally provided and stored in eggs and that the regulation of its synthesis in embryos was independent on the amount of its mRNA.