Global Transcriptional Repression in C. elegans Germline Precursors by Regulated Sequestration of TAF-4

Tugba Guven-Ozkan, Yuichi Nishi, Scott M. Robertson, Rueyling Lin

Research output: Contribution to journalArticle

70 Scopus citations


In C. elegans, four asymmetric divisions, beginning with the zygote (P0), generate transcriptionally repressed germline blastomeres (P1-P4) and somatic sisters that become transcriptionally active. The protein PIE-1 represses transcription in the later germline blastomeres but not in the earlier germline blastomeres P0 and P1. We show here that OMA-1 and OMA-2, previously shown to regulate oocyte maturation, repress transcription in P0 and P1 by binding to and sequestering in the cytoplasm TAF-4, a component critical for assembly of TFIID and the pol II preinitiation complex. OMA-1/2 binding to TAF-4 is developmentally regulated, requiring phosphorylation by the DYRK kinase MBK-2, which is activated at meiosis II after fertilization. OMA-1/2 are normally degraded after the first mitosis, but ectopic expression of wild-type OMA-1 is sufficient to repress transcription in both somatic and later germline blastomeres. We propose that phosphorylation by MBK-2 serves as a developmental switch, converting OMA-1/2 from oocyte to embryo regulators.

Original languageEnglish (US)
Pages (from-to)149-160
Number of pages12
Issue number1
StatePublished - Oct 3 2008



  • DNA

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

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