ABSTRACT
In Mus spretus, the chloride channel 4 gene Clcn4-2 is X-linked and dosage compensated by X up-regulation and X inactivation, while in the closely related mouse species Mus musculus, Clcn4-2 has been translocated to chromosome 7. We sequenced Clcn4-2 in M. spretus and identified the breakpoints of the evolutionary translocation in the Mus lineage. Genetic and epigenetic differences were observed between the 5'ends of the autosomal and X-linked loci. Remarkably, Clcn4-2 introns have been truncated on chromosome 7 in M. musculus as compared with the X-linked loci from seven other eutherian mammals. Intron sequences specifically preserved in the X-linked loci were significantly enriched in AT-rich oligomers. Genome-wide analyses showed an overall enrichment in AT motifs unique to the eutherian X (except for genes that escape X inactivation), suggesting a role for these motifs in regulation of the X chromosome.
Subject(s)
Chloride Channels/genetics , 5' Flanking Region/genetics , AT Rich Sequence , Animals , Base Sequence , Chloride Channels/metabolism , Chromosome Breakage , Chromosome Mapping , Dosage Compensation, Genetic , Epigenomics , Evolution, Molecular , Female , Gene Dosage , Genes , Genome , Humans , Introns , Male , Mice , Molecular Sequence Data , Muridae , Protein Structure, Tertiary/genetics , Rats , Sequence Analysis, DNA , Species Specificity , X Chromosome/geneticsABSTRACT
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