Transcriptional quiescence, an evolutionarily conserved trait, distinguishes the embryonic primordial germ cells (PGCs) from their somatic neighbors. In , PGCs from embryos maternally compromised for () misexpress somatic genes, possibly resulting in PGC loss. Recent studies documented a requirement for Gcl during proteolytic degradation of the terminal patterning determinant, Torso receptor.
View Article and Find Full Text PDFThe binary switch gene Sex-lethal (Sxl) controls sexual identity in Drosophila. When activated, Sxl imposes female identity, whereas male identity ensues by default when the gene is off. The decision to activate Sxl is controlled by an X chromosome counting system that regulates the Sxl establishment promoter, Sxl-Pe.
View Article and Find Full Text PDFBoundary elements or insulators subdivide eukaryotic chromosomes into a series of structurally and functionally autonomous domains. They ensure that the action of enhancers and silencers is restricted to the domain in which these regulatory elements reside. Three models, the roadblock, sink/decoy, and topological loop, have been proposed to explain the insulating activity of boundary elements.
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