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Transient requirements of YY1 expression for PcG transcriptional repression and phenotypic rescue
Author(s) -
Srinivasan Lakshmi,
Pan Xuan,
Atchison Michael L.
Publication year - 2005
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.20562
Subject(s) - psychological repression , yy1 , biology , imaginal disc , microbiology and biotechnology , genetics , mutant , transcription factor , transcriptional regulation , drosophila melanogaster , phenotype , regulation of gene expression , histone , gene , promoter , gene expression
A hallmark of PcG transcriptional repression is stability of the repressed state, although the mechanism of this stability is unclear. The mammalian transcription factor YY1 can function as a PcG protein in Drosophila resulting in transcriptional repression and correction of phenotypic defects caused by mutation of its homologue, Pleiohomeotic (PHO). To discern the temporal requirements of YY1 expression for these functions, and to study its mechanism of stable repression in vivo, we used a Drosophila larval wing imaginal disc transcriptional repression system. We found that YY1 was needed transiently at day 3 or later of embryonic development to stably repress a reporter transgene at day 8 in wing imaginal discs. Stable transcriptional repression did not correlate with maintenance of YY1 or Polycomb DNA binding, but did correlate with persistence of histone H3 methylation on lysine 27. We also found that YY1 expressed during the first 7 days of development was sufficient for rescue of fly development (a 14 day process) in pho mutant flies. Therefore, YY1 was transiently required for correction of fly defects and was dispensable past the pharate adult stage. Possible mechanisms of repression by YY1 are discussed. © 2005 Wiley‐Liss, Inc.