EARLY EMBRYONIC EXPRESSION OF XLPOU-60, A XENOPUS POU-DOMAIN PROTEIN

XLPOU-60 is a Xenopus POU-domain gene whose expression is tightly cont rolled during early development at transcriptional, post-transcription al, translational, and post-translational levels. We report the expres sion pattern of the XLPOU-60 protein; it is first detectable in the st age V oocyte and accumulates rapidly following fertilisation, reaching a peak at the time of the mid-blastula transition. In the blastula, X LPOU-60 protein translated from injected synthetic mRNA enters nuclei. During gastrulation, both transcript and protein are rapidly down-reg ulated in a cell-autonomous manner; down-regulation is not dependent o n cell-cell contact or induction by activin in an animal cap assay. Fo r the mRNA, this down-regulation correlates with changes in the length of its poly(A) tail and is dependent on sequences in the untranslated regions of the transcript. On the basis of its protein expression pat tern and known DNA-binding properties, we speculate that XLPOU-60 may play a role in the control of early transcriptional events in the Xeno pus embryo. (C) 1995 Academic Press, Inc.