[HTML][HTML] Developmentally regulated subnuclear genome reorganization restricts neural progenitor competence in Drosophila

M Kohwi, JR Lupton, SL Lai, MR Miller, CQ Doe - Cell, 2013 - cell.com
M Kohwi, JR Lupton, SL Lai, MR Miller, CQ Doe
Cell, 2013cell.com
Stem and/or progenitor cells often generate distinct cell types in a stereotyped birth order
and over time lose competence to specify earlier-born fates by unknown mechanisms. In
Drosophila, the Hunchback transcription factor acts in neural progenitors (neuroblasts) to
specify early-born neurons, in part by indirectly inducing the neuronal transcription of its
target genes, including the hunchback gene. We used in vivo immuno-DNA FISH and found
that the hunchback gene moves to the neuroblast nuclear periphery, a repressive …
Summary
Stem and/or progenitor cells often generate distinct cell types in a stereotyped birth order and over time lose competence to specify earlier-born fates by unknown mechanisms. In Drosophila, the Hunchback transcription factor acts in neural progenitors (neuroblasts) to specify early-born neurons, in part by indirectly inducing the neuronal transcription of its target genes, including the hunchback gene. We used in vivo immuno-DNA FISH and found that the hunchback gene moves to the neuroblast nuclear periphery, a repressive subnuclear compartment, precisely when competence to specify early-born fate is lost and several hours and cell divisions after termination of its transcription. hunchback movement to the lamina correlated with downregulation of the neuroblast nuclear protein, Distal antenna (Dan). Either prolonging Dan expression or disrupting lamina interfered with hunchback repositioning and extended neuroblast competence. We propose that neuroblasts undergo a developmentally regulated subnuclear genome reorganization to permanently silence Hunchback target genes that results in loss of progenitor competence.
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