Hiura Hitoshi, Komiyama Junichi, Shirai Motomu, Obata Yayoi, Ogawa Hidehiko, Kono Tomohiro
Department of BioScience, Tokyo University of Agriculture, 1-1-1, Sakuragaoka, Tokyo 156-8502, Japan.
FEBS Lett. 2007 Apr 3;581(7):1255-60. doi: 10.1016/j.febslet.2007.02.034. Epub 2007 Feb 28.
Mouse genomes show a large cluster of imprinted genes at the Dlk1-Gtl2 domain in the distal region of chromosome 12. An intergenic-differentially methylated region (IG-DMR) located between Dlk1 and Gtl2 is specifically methylated in the male germline; IG-DMR regulates the parental allele-specific expression of imprinted genes. Here, we show the resetting of IG-DMR methylation marks during male germ-cell differentiation. For parental allele-specific methylation analysis, polymorphisms were detected in a 2.6-kb IG-DMR in three mouse strains. Bisulfite methylation analysis showed erasure of the marks by E14 and re-establishment before birth. The IG-DMR methylation status was maintained in spermatogonia and spermatocytes of mature testes. The IG-DMR methylation status established before birth is thus maintained throughout the lifetime in the male germline.
小鼠基因组在12号染色体远端区域的Dlk1 - Gtl2结构域显示出大量印记基因簇。位于Dlk1和Gtl2之间的基因间差异甲基化区域（IG - DMR）在雄性生殖系中特异性甲基化；IG - DMR调节印记基因的亲本等位基因特异性表达。在此，我们展示了雄性生殖细胞分化过程中IG - DMR甲基化标记的重设。为了进行亲本等位基因特异性甲基化分析，在三个小鼠品系的2.6 kb IG - DMR中检测到多态性。亚硫酸氢盐甲基化分析显示，这些标记在E14时被消除，并在出生前重新建立。IG - DMR甲基化状态在成熟睾丸的精原细胞和精母细胞中得以维持。因此，出生前建立的IG - DMR甲基化状态在雄性生殖系中终生维持。
