First published online October 30, 2006
Development 133, 2202e (2006)
© The Company of Biologists Limited
SCF opens up for dosage compensation
In Drosophila, equal gene expression from the sex chromosomes in
males and females (dosage compensation) is achieved by hypertranscription from
the single X chromosome in male flies. Furuhashi and colleagues now identify
DNA supercoiling factor (SCF), a protein that generates negative supercoils in
DNA, as an important player in this process (see
p. 4475). They show
that SCF knockdown by RNAi causes male-specific reduction of X-linked gene
expression and male lethality. SCF, they report, colocalizes along the X
chromosome with the male-specific lethality (MSL) complex, which is required
for dosage compensation, and overexpression of SCF gives the X chromosome a
bloated appearance. This phenotype depends on the MSL component MOF, a histone
acetyltransferase, and is suppressed by overexpression of the chromatin
remodelling protein ISWI, which antagonizes MOF activity. The researchers
conclude that by counteracting ISWI action, SCF helps to form and/or maintain
the transcriptionally active open chromatin that is needed for X chromosome
hypertranscription in male flies.
Related articles in Development:
- DNA supercoiling factor contributes to dosage compensation in Drosophila
- Hirofumi Furuhashi, Mikage Nakajima, and Susumu Hirose
Development 2006 133: 4475-4483.
[Abstract]
[Full Text]
