Abnormal DNA Methyltransferase Expression in Mouse Germline Stem Cells Results in Spermatogenic Defects
Abnormal DNA Methyltransferase Expression in Mouse Germline Stem Cells Results in Spermatogenic Defects
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DOI：
10.1095/biolreprod.108.074708
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发表时间：
2009-07-01
影响因子：
3.6
通讯作者：
Shinohara, Takashi
中科院分区：
文献类型：
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作者：
Takashima, Seiji;Takehashi, Masanori;Shinohara, Takashi
虽然精原干细胞（SSCs）致力于精子发生，但它们也可以低频率转化为胚胎干细胞样多能状态。由于DNA甲基化模式的变化与这种转换有关，我们研究了操纵DNA甲基转移酶（Dnmt）表达对培养的SSC（生殖系干细胞（GS）细胞）命运的影响。Dnmt 1敲低诱导GS细胞凋亡，这是衰减的Trp 53的损失。相反，GS细胞在Dnmt 3a/Dnmt 3b消融后或在Dnmt 3l过表达期间在体外正常增殖。然而，Dnmt 3a/Dnmt 3b双突变细胞在SineB 1重复序列中表现出低甲基化，而Dnmt 3l过表达细胞在主要和次要卫星序列中表现出高甲基化;两种细胞类型都没有形成畸胎瘤，并在移植到曲细精管后完成精子发生。虽然遗传操作并没有增加GS细胞向多能状态的转化，但这些结果强调了DNMT在精原干细胞存活和生精分化中的重要作用。
Although spermatogonial stem cells (SSCs) are committed to spermatogenesis, they may also convert to an embryonic stem cell-like pluripotent state at a low frequency. Because changes in DNA methylation patterns are associated with this conversion, we examined the effect of manipulating DNA methyltransferase (Dnmt) expression on the fate of cultured SSCs, germline stem (GS) cells. Dnmt1 knockdown induced apoptosis in GS cells, which was attenuated by the loss of Trp53. In contrast, GS cells proliferated normally in vitro after Dnmt3a/Dnmt3b ablation or during Dnmt3l overexpression. However, Dnmt3a/Dnmt3b double-mutant cells showed hypomethylation in the SineB1 repetitive sequence, and Dnmt3l-overexpressing cells showed hypermethylation in major and minor satellite sequences; neither cell type formed teratomas and completed spermatogenesis following transplantation into the seminiferous tubules. Although genetic manipulation did not increase the conversion of GS cells to a pluripotent state, these results underscore the important role of DNMTs in survival and spermatogenic differentiation in SSCs.