Department of Pathology, University of Washington, Seattle, Washington 98195, USA.
Genome Res. 2011 Mar;21(3):402-9. doi: 10.1101/gr.108563.110. Epub 2011 Jan 31.
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.
在 Mus spretus 中，氯离子通道 4 基因 Clcn4-2 是 X 连锁的，并通过 X 上调和 X 失活来进行剂量补偿，而在密切相关的鼠种 Mus musculus 中，Clcn4-2 已被转移到染色体 7 上。我们对 M. spretus 中的 Clcn4-2 进行了测序，并确定了 Mus 谱系中进化易位的断点。在常染色体和 X 连锁基因座的 5'端观察到遗传和表观遗传差异。值得注意的是，与其他七个真兽类哺乳动物的 X 连锁基因座相比，M. musculus 染色体 7 上的 Clcn4-2 内含子已被截断。在 X 连锁基因座中特异性保存的内含子序列富含富含 AT 的低聚物。全基因组分析显示，除了逃避 X 失活的基因外，真兽类 X 特有的 AT 基序总体上富集，这表明这些基序在 X 染色体调控中起作用。
