Role of histone H3K4 demethylase KDM1B for oocyte-specific imprinting in mice

为了了解组蛋白H3K4去甲基化酶KDM1B在卵母细胞特异性印迹中的作用，分析了卵母细胞生长过程中KDM1B的表达，并在DNA甲基转移酶（DNMTs）过表达的条件下检查了Zac1和Mest基因座甲基化印迹的建立。结果表明，KDM1B mRNA在非生长期卵母细胞中高水平表达，而KDM1B蛋白在生长期以后才开始表达。过量的DNMT诱导早期获得DNA甲基化印记在Zac1，但不是Mest在早期生长的卵母细胞。因此，我们揭示了DNMT和KDM1B的存在是必要的，但不足以建立卵母细胞特异性印迹。

To understand the role of histone H3K4 demethylase KDM1B for oocyte-specific imprinting, expression of KDM1B during oocyte growth was analyzed and the establishment of methylation imprints in Zac1 and Mest loci were examined under conditions of DNA methyltransferases (DNMTs) overexpression. The results showed that KDM1B mRNA was expressed at a high level in oocytes from the non-growing stage but KDM1B protein was expressed from the growth stage onward. Excess of DNMTs induced early acquisition of DNA methylation imprints at Zac1 but not Mest in early-growing oocytes. Thus, we revealed that the presence of DNMTs and KDM1B is essential but not sufficient for establishment of oocyte-specific imprinting.