Spermatogenesis is a differentiation process during which diploid spermatogonial stem cells (SSCs) produce haploid spermatozoa. This highly specialized process is precisely controlled at the transcriptional, posttranscriptional, and translational levels. Here we report that N⁶-methyladenosine (m⁶A), an epitranscriptomic mark regulating gene expression, plays essential roles during spermatogenesis. We present comprehensive m⁶A mRNA methylomes of mouse spermatogenic cells from five developmental stages: undifferentiated spermatogonia, type A₁ spermatogonia, preleptotene spermatocytes, pachytene/diplotene spermatocytes, and round spermatids. Germ cell-specific inactivation of the m⁶A RNA methyltransferase Mettl3 or Mettl14 with Vasa-Cre causes loss of m⁶A and depletion of SSCs. m⁶A depletion dysregulates translation of transcripts that are required for SSC proliferation/differentiation. Combined deletion of Mettl3 and Mettl14 in advanced germ cells with Stra8-GFPCre disrupts spermiogenesis, whereas mice with single deletion of either Mettl3 or Mettl14 in advanced germ cells show normal spermatogenesis. The spermatids from double-mutant mice exhibit impaired translation of haploid-specific genes that are essential for spermiogenesis. This study highlights crucial roles of mRNA m⁶A modification in germline development, potentially ensuring coordinated translation at different stages of spermatogenesis.

中文翻译：

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Mettl3-/Mettl14 介导的 mRNA N6-甲基腺苷调节小鼠精子发生。

精子发生是二倍体精原干细胞 (SSC) 产生单倍体精子的分化过程。这种高度专业化的过程在转录、转录后和翻译水平上受到精确控制。在这里我们报告 N ⁶ -甲基腺苷(m ⁶ A)，一种调节基因表达的表观转录组标记，在精子发生过程中起着重要作用。我们展示了来自五个发育阶段的小鼠生精细胞的综合 m ⁶ A mRNA 甲基化组：未分化的精原细胞、A _{1 型}精原细胞、前细线期精母细胞、粗线期/双线期精母细胞和圆形精细胞。m ^{6 的}生殖细胞特异性失活带有 Vasa-Cre 的 RNA 甲基转移酶 Mettl3 或 Mettl14 会导致 m ⁶ A丢失和 SSC 消耗。m ⁶耗竭会失调 SSC 增殖/分化所需的转录本的翻译。Stra8-GFPCre 联合删除晚期生殖细胞中的 Mettl3 和 Mettl14 会破坏精子发生，而晚期生殖细胞中单独删除 Mettl3 或 Mettl14 的小鼠显示正常的精子发生。双突变小鼠的精子细胞表现出对精子发生必不可少的单倍体特异性基因的翻译受损。这项研究强调了 mRNA m ⁶ A 修饰在生殖系发育中的关键作用，可能确保在精子发生的不同阶段进行协调翻译。