Epigenetic Temporal Control of Mouse Hox Genes in Vivo
Natalia Soshnikova1 and
Denis Duboule1,2,*
During vertebrate development, the temporal control of
Hox gene
transcriptional activation follows the genomic order of the
genes within the
Hox clusters. Although it is recognized that
this "
Hox clock" serves to coordinate body patterning, the underlying
mechanism remains elusive. We have shown that successive
Hox gene activation in the mouse embryo is closely associated with
a directional transition in chromatin status, as judged by the
dynamic progression of transcription-competent modifications:
Increases in activation marks correspond to decreases in repressive
marks. Furthermore, using a mouse in which a
Hox cluster was
split into two pieces, we document the necessity to maintain
a clustered organization to properly implement this process.
These results suggest that chromatin modifications are important
parameters in the temporal regulation of this gene family.
2 National Research Centre Frontiers in Genetics, School of Life Sciences, Federal Institute of Technology (EPFL), Lausanne, Switzerland.
* To whom correspondence should be addressed. E-mail: Denis.Duboule{at}unige.ch; Denis.Duboule{at}epfl.ch
