First published online November 24, 2004
Development 131, 2405e (2004)
© The Company of Biologists Limited
Staying silent in early development
During early amphibian embryogenesis, transcription from zygotic genes is
repressed until the midblastula transition. DNA methylation is thought to
underlie this repression: methyl-CpG-specific binding proteins interact with
methylated DNA and recruit enzymes that promote the formation of inactive
chromatin. Ruzov and colleagues now report that xKaiso, which binds
specifically to methyl-CpG through a zinc-finger domain, maintains
transcriptional silencing during the first 12 cleavage stages in
Xenopus embryos (see p.
6185). The depletion
of xKaiso function in early embryos by morpholinos results in zygotic gene
expression beginning at least two cell cycles before the midblastula
transition, and also in developmental arrest and apoptosis. This phenotype,
which resembles that seen in hypomethylated embryos, is rescued by the
injection of human kaiso mRNA. The researchers conclude that xKaiso controls
this early genome-wide methylation-dependent transcriptional silencing, which
is essential for amphibian development.
Related articles in Development:
- Kaiso is a genome-wide repressor of transcription that is essential for amphibian development
- Alexey Ruzov, Donncha S. Dunican, Anna Prokhortchouk, Sari Pennings, Irina Stancheva, Egor Prokhortchouk, and Richard R. Meehan
Development 2004 131: 6185-6194.
[Abstract]
[Full Text]
