Post-transcriptional regulation of Xwnt-8 expression is required for normal myogenesis during vertebrate embryonic development.
The Xenopus Wnt-8 gene is transiently expressed in ventral and lateral mesoderm during gastrulation and plays a critical role in patterning these tissues. In the current study, we show that the spatial and temporal pattern of expression of endogenous Xwnt-8 is regulated, in part, at a post-transcriptional level. We have identified a novel sequence element in the 3' untranslated region of the Xwnt-8 RNA that controls the polyadenylation status of reporter and endogenous Xwnt-8 RNAs, directs rapid RNA degradation beginning precisely at the early gastrula stage, and represses translation of transcripts throughout development. Expression of endogenous Xwnt-8 is normally downregulated within lateral (presomitic) mesoderm following gastrulation. We demonstrate that rapid degradation of Xwnt-8 transcripts, mediated by these regulatory elements in the 3' untranslated region, is essential to this process and that downregulation is required to prevent overcommitment of somitic cells to a myogenic fate. These studies demonstrate a role for post-transcriptional regulation of zygotic gene expression in vertebrate embryonic patterning.
Department of Cell and Developmental Biology, L215, Oregon Health Sciences University, School of Medicine, Portland, OR 97201-3098, USA.
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Tian
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Nakayama
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Dixon
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JL
Christian
D020413:3' Untranslated Regions; D000818:Animals; D001483:Base Sequence; D019521:Body Patterning / Q000235:genetics; D003513:Cycloheximide / Q000494:pharmacology; D017931:DNA Primers / Q000235:genetics; D005260:Female; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D008969:Molecular Sequence Data; D009132:Muscles / Q000196:embryology*; D014176:Protein Biosynthesis; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D012313:RNA / Q000235:genetics / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional / Q000187:drug effects; D017384:Sequence Deletion; D051153:Wnt Proteins; D014981:Xenopus / Q000196:embryology* / Q000235:genetics* / Q000378:metabolism; D029867:Xenopus Proteins; D029961:Zebrafish Proteins
D020413:3' Untranslated Regions; D017931:DNA Primers; D011500:Protein Synthesis Inhibitors; D011518:Proto-Oncogene Proteins; D051153:Wnt Proteins; D029867:Xenopus Proteins; D029961:Zebrafish Proteins; C495248:wnt8a protein, Xenopus; D012313:RNA; D003513:Cycloheximide