Potential role of miR-29b in modulation of Dnmt3a and Dnmt3b expression in primordial germ cells of female mouse embryos
Potential role of miR-29b in modulation of Dnmt3a and Dnmt3b expression in primordial germ cells of female mouse embryos
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DOI：
10.1261/rna.1418309
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发表时间：
2009-08-01
期刊：
影响因子：
4.5
通讯作者：
Mano, Hiroyuki
中科院分区：
文献类型：
--
作者：
Takada, Shuji;Berezikov, Eugene;Mano, Hiroyuki
microRNAs（miRNAs）是近年来发现的一类小分子非编码RNA，参与越来越多的生物学过程。为了研究miRNAs是否可能有助于性分化，我们使用高度敏感的克隆方法mRAP对小鼠胚胎性腺中的miRNAs进行了表达谱分析。我们的分析数据显示，在胚胎（E）第13.5天（E13.5），雄性和雌性性腺之间的miRNA库存在显著差异，表明这种差异表达的miRNA可能在性分化中起作用。雌性特异性miRNA包括miR-29 b，已知其也以类似的性别依赖性方式在鸡胚胎的性腺中表达，提示在性腺发生中的保守作用。人类从头甲基转移酶DNMT 3A和DNMT 3B基因的转录物已被鉴定为miR-29 b的靶标，并且我们发现小鼠miR-29 b也在荧光素酶报告基因测定中负调控Dnmt 3a和Dnmt 3b表达。我们还发现miR-29 b在E13.5时在小鼠原始生殖细胞（PGC）中表达，并且其表达在E13.5和E17.5之间以女性特异性方式上调，此时已知PGC基因组发生男性特异性从头甲基化。因此，我们的数据表明，miR-29 b可能通过靶向Dnmt 3a和Dnmt 3b，从而调节PGCs中基因组DNA的甲基化，在女性性腺发育中发挥重要作用。
MicroRNAs (miRNAs) are a recently discovered class of small noncoding RNAs and are implicated in an increasing number of biological processes. To examine whether miRNAs might contribute to sexual differentiation, we performed expression profiling of miRNAs in mouse embryonic gonads with the use of a highly sensitive cloning method, mRAP. Our profiling data revealed substantial differences in the miRNA repertoire between male and female gonads at embryonic (E) day 13.5 (E13.5), suggesting that such differentially expressed miRNAs may function in sexual differentiation. Female-specific miRNAs included miR-29b, which also has been known to be expressed in a similar sex-dependent manner in the gonads of chicken embryos, suggestive of a conserved role in gonadogenesis. Transcripts of the human genes for the de novo methyltransferases DNMT3A and DNMT3B have been identified as targets of miR-29b, and we found that mouse miR-29b also negatively regulates Dnmt3a and Dnmt3b expression in luciferase reporter assays. We also found that miR-29b is expressed in mouse primordial germ cells (PGCs) at E13.5 and that its expression is up-regulated in a female-specific manner between E13.5 and E17.5, when male-specific de novo methylation of the PGC genome is known to occur. Our data thus suggest that miR-29b may play an important role in female gonadal development by targeting Dnmt3a and Dnmt3b and thereby modulating methylation of genomic DNA in PGCs.