Stra8 and its inducer, retinoic acid, regulate meiotic initiation in both spermatogenesis and oogenesis in mice
Stra8 and its inducer, retinoic acid, regulate meiotic initiation in both spermatogenesis and oogenesis in mice
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DOI：
10.1073/pnas.0807297105
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发表时间：
2008-09-30
影响因子：
11.1
通讯作者：
Page, David C.
中科院分区：
文献类型：
--
作者：
Anderson, Ericka L.;Baltus, Andrew E.;Page, David C.
在真核生物中，二倍体细胞通过减数分裂产生单倍体细胞，减数分裂是一个在一轮DNA复制之前的两次细胞分裂的程序。虽然减数分裂器的关键分子组分在真核生物中是高度保守的，但负责启动减数分裂程序的机制在真核生物中有很大差异。这就在具有两种不同性别的动物中提出了一个相关的问题：在一个给定的物种中，雄性和雌性生殖细胞系中使用的减数分裂起始机制是相似的还是不同的？在哺乳动物中，雄性和雌性减数分裂起始时间的巨大差异突出了这个问题。Stra 8是一种脊椎动物特异性的细胞质因子，由生殖细胞响应视黄酸表达。我们以前证明，Stra 8基因的功能是必需的小鼠胚胎卵巢减数分裂起始。在这里，我们报告说，在近交系C57 BL/6的遗传背景下，同样的因素也需要在幼年小鼠睾丸生殖细胞减数分裂的启动。在青少年C57 BL/6男性缺乏Stra 8基因功能，生殖细胞的早期有丝分裂发育似乎是不受干扰的。然而，这些细胞不能经历定义减数分裂前期的形态学变化，并且它们不显示减数分裂染色体凝聚、突触和重组的分子标志。我们的结论是，在小鼠中，Stra 8调节减数分裂启动精子发生和卵子发生。与以前的观察一起，我们目前的研究结果表明，在男性和女性生殖系，减数分裂是通过视黄酸诱导的Stra 8。
In eukaryotes, diploid cells give rise to haploid cells via meiosis, a program of two cell divisions preceded by one round of DNA replication. Although key molecular components of the meiotic apparatus are highly conserved among eukaryotes, the mechanisms responsible for initiating the meiotic program have diverged substantially among eukaryotes. This raises a related question in animals with two distinct sexes: Within a given species, are similar or different mechanisms of meiotic initiation used in the male and female germ lines? In mammals, this question is underscored by dramatic differences in the timing of meiotic initiation in males and females. Stra8 is a vertebrate-specific, cytoplasmic factor expressed by germ cells in response to retinoic acid. We previously demonstrated that Stra8 gene function is required for meiotic initiation in mouse embryonic ovaries. Here we report that, on an inbred C57BL/6 genetic background, the same factor is also required for meiotic initiation in germ cells of juvenile mouse testes. In juvenile C57BL/6 males lacking Stra8 gene function, the early mitotic development of germ cells appears to be undisturbed. However, these cells then fail to undergo the morphological changes that define meiotic prophase, and they do not display the molecular hallmarks of meiotic chromosome cohesion, synapsis and recombination. We conclude that, in mice, Stra8 regulates meiotic initiation in both spermatogenesis and oogenesis. Taken together with previous observations, our present findings indicate that, in both the male and female germ lines, meiosis is initiated through retinoic acid induction of Stra8.