Male-specific function of Dmrt7 by sexually dimorphic translation in mouse testis
Male-specific function of Dmrt7 by sexually dimorphic translation in mouse testis
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DOI：
10.1159/000108932
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发表时间：
2007-01-01
影响因子：
2.3
通讯作者：
Nishimori, K.
中科院分区：
文献类型：
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作者：
Kawamata, M.;Inoue, H.;Nishimori, K.
Dmrt 7基因在睾丸和卵巢中均有表达，但在精子发生中是必需基因，而在卵子发生中不是必需基因。在这项研究中，我们进一步研究了Dmrt 7转录本和蛋白质的表达。北方杂交和RT- PCR分析表明，成年睾丸中除了成熟的mRNA外，还存在一个具有内含子1全序列的选择性剪接变体（内含子1变体）。在胎儿卵巢中，内含子1变体不表达，而完全剪接形式的mRNA表达。免疫组织化学分析表明，DMRT 7蛋白只存在于成年睾丸精母细胞，而不是在胎儿卵巢。原位杂交分析表明，完全剪接形式的Dmrt 7 mRNA以及内含子1的变体表达在精原细胞，精子细胞和支持细胞，除了精母细胞。我们还发现Dmrt 7 mRNA的poly（A）尾经历了长度从70到440 bp的修饰。与Arbp mRNA不同，在精子细胞缺失的未成熟睾丸中观察到poly（A）尾的大小变化。在这项研究中，我们证明了Dmrt 7在与精母细胞特异性翻译相关的转录本中具有独特的性二态性表达模式，但在卵巢中没有。版权所有（C）2007 S. Karger AG，巴塞尔。
Dmrt7 is known to be an essential gene for spermatogenesis but not for oogenesis despite mRNA expression in both testis and ovary. In this study, we examined further expression of Dmrt7 transcript and protein. Northern blot and RT- PCR analysis revealed that there was an alternative splicing variant possessing the entire sequence of intron 1 in adult testis ( intron 1 variant), in addition to the mature form of mRNA. In fetal ovary, the intron 1 variant was not expressed whereas the fully spliced form of mRNA was expressed. Immunohistochemical analyses demonstrated that DMRT7 protein was present only in spermatocytes of adult testis but not in fetal ovary. In situ hybridization analyses revealed that the fully spliced form of Dmrt7 mRNA as well as the intron 1 variant were expressed in spermatogonia, spermatids and Sertoli cells in addition to spermatocytes. We also found that poly( A) tails of Dmrt7 mRNA underwent modification of its length from 70 to 440 bp long. Unlike Arbp mRNA, the size variation of poly( A) tails was observed in immature testis in which spermatids were absent. In this study, we demonstrated that Dmrt7 had unique sexually dimorphic expression patterns in transcripts that associated with spermatocyte- specific translation, but not in ovary. Copyright (C) 2007 S. Karger AG, Basel.