First published online January 11, 2008
Development 135, 304e (2008)
© The Company of Biologists Limited
BRG1 opens up primitive erythropoiesis
During development, ATP-dependent chromatin-remodelling complexes control
certain temporal and spatial changes in gene expression that drive
differentiation. Mammalian SWI-SNF-like chromatin-remodelling complexes
contain one of two ATPase subunits: brahma (BRM) or brahma-related gene 1
(BRG1). Now, Griffin and colleagues report that BRG1-containing SWI-SNF-like
complexes are required for primitive erythropoiesis and early vascular
development in mice (see p.
493). The researchers show that when Brg1 is conditionally
deleted in developing haematopoietic and endothelial cells, mouse embryos die
at midgestation from anaemia. The primitive erythrocytes in these embryos fail
to transcribe embryonic
- and β-globins, they report, and
subsequently undergo apoptosis. Vascular remodelling in the extra-embryonic
yolk sac of Brg1 mutant embryos is also abnormal, but the additional
loss of Brm does not exacerbate their erythropoietic or vascular
abnormalities. These results extend previous experiments in which hypomorphic
Brg1 mutations prevented the transcription of adult but not of
embryonic β-globin genes, note the researchers, and reveal non-redundant
roles for BRM and BRG1 during primitive erythropoiesis and early vascular
development.
Related articles in Development:
- The chromatin-remodeling enzyme BRG1 plays an essential role in primitive erythropoiesis and vascular development
- Courtney T. Griffin, Jennifer Brennan, and Terry Magnuson
Development 2008 135: 493-500.
[Abstract]
[Full Text]