Testicular oocytes in MRL/MpJ mice possess similar morphological, genetic, and functional characteristics to ovarian oocytes
Testicular oocytes in MRL/MpJ mice possess similar morphological, genetic, and functional characteristics to ovarian oocytes
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MRL/MpJ 小鼠的睾丸卵母细胞与卵巢卵母细胞具有相似的形态、遗传和功能特征
DOI：
10.1016/j.mod.2015.04.002
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Kon Y
中科院分区：
文献类型：
--
作者：
Otsuka-Kanazawa S;Ichii O;Kon Y
一般来说，雄性哺乳动物的睾丸仅产生精子，雌性哺乳动物的卵巢仅产生卵母细胞。然而，新生的 MRL/MpJ 雄性小鼠的睾丸内会产生卵母细胞。在这项研究中，我们检查了胎儿和新生儿 MRL/MpJ 小鼠睾丸卵子发生的起始和进展，并评估了睾丸卵母细胞的特征。在胚胎第 18.5 天的 MRL/MpJ 胎儿睾丸中观察到对卵子发生标记物（如 NOBOX 卵子发生同源盒和联会复合蛋白 3）呈阳性反应的生殖细胞。这些胎儿睾丸卵母细胞具有母体特异性的组蛋白和 DNA 甲基化模式。出生后第 14 天，出生后睾丸卵母细胞的 DNA 甲基化水平仍然较低。此外，出生后的睾丸卵母细胞含有X和Y染色体，并且具有与精子融合的能力。这些结果表明，MRL/MpJ 小鼠胎儿睾丸中的一些 XY 生殖细胞过早进入减数分裂，经历卵子发生并分化为卵母细胞。此外，MRL/MpJ睾丸卵母细胞有能力在出生前和出生后不久进行卵子发生，直到获得卵母细胞的一些形态、表观遗传和功能特征。
In general, mammalian males produce only spermatozoa in their testes and females produce only oocytes in their ovaries. However, newborn MRL/MpJ male mice produce oocytes within their testes. In this study, we examined the initiation and progression of oogenesis in fetal and neonatal MRL/MpJ mouse testes and evaluated the characteristics of testicular oocytes. Germ cells with positive reactions to oogenesis markers such as NOBOX oogenesis homeobox and synaptonemal complex protein 3 were observed in the MRL/MpJ fetal testes on embryonic day 18.5. These fetal testicular oocytes possessed maternal-specific methylation patterns of histone and DNA. The level of DNA methylation was still low in postnatal testicular oocytes at day 14 after birth. Additionally, the postnatal testicular oocytes contained both X and Y chromosomes and had the ability to fuse with sperm. These results suggest that some XY germ cells in fetal testes of MRL/MpJ mice enter meiosis prematurely, undergo oogenesis, and differentiate into oocytes. In addition, MRL/MpJ testicular oocytes have the ability to carry on oogenesis before and shortly after birth until they obtain some of the morphological, epigenetic, and functional characteristics of oocytes.