Conservation of large foci formation in arrested oocytes of Caenorhabditis nematodes
Conservation of large foci formation in arrested oocytes of Caenorhabditis nematodes
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DOI：
10.1007/s00427-006-0130-3
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发表时间：
2007-03-01
影响因子：
2.4
通讯作者：
Schisa, Jennifer A.
中科院分区：
文献类型：
--
作者：
Jud, Molly;Razelun, Jamie;Schisa, Jennifer A.
在线虫的小杆线虫发生中，绝大多数物种是雌雄异株的，进化为专性雄性/雌性物种。相比之下，线虫模型系统，秀丽隐杆线虫，是雌雄异株的，利用雌雄同体/男性生殖系统。我们以前已经确定，在老年C。秀丽线虫雌雄同体，精子减少，形成大的胞质核糖核蛋白灶。这些病灶的形成是可逆的，因为它们在雄性与雌雄同体交配后3小时内解离，重新为其提供精子。这些卵母细胞灶的功能意义尚不清楚，以前还不清楚的雌雄同体的物种中，年轻的成年人的卵母细胞只等待约23分钟受精。一种假设是，当受精延迟时，灶的功能是维持卵母细胞中的母体mRNA。在本文中，我们研究了四个gonochoristic小杆虫物种：Caushabditis remanei，Caushabditis sp. CB5161，Caushabditis sp. PS1010，和Rhabditella axei DF5006。我们证明，在这四个物种中的三个，排卵逮捕在未交配的女性，直到交配发生和大的细胞质病灶发展被捕的卵母细胞。卵母细胞灶含有核孔蛋白，在C.至少，RNA结合蛋白MEX-3以及RNA。我们推测，这些病灶保持完整的卵母细胞，可能保持稳定或翻译抑制的母体mRNA在未交配的女性。我们进一步推测，它们的存在，在卵母细胞的老年C。elegans hermaphrodites是由于从一个祖先的雌雄异体状态的保护。
Within the rhabditid phylogeny of nematodes, the great majority of species are gonochoristic, having evolved as obligate male/female species. In contrast, the well-studied nematode model system, Caenorhabditis elegans, is androdioecious, utilizing a hermaphroditic/male reproductive system. We have previously determined that in the arrested oocytes of old-aged C. elegans hermaphrodites with depleted sperm, large cytoplasmic ribonucleoprotein foci form. The formation of these foci is reversible, as they dissociate within 3 h after a male mates with the hermaphrodite, resupplying it with sperm. The functional significance of these oocyte foci is not known and previously has not been clear for a hermaphroditic species in which oocytes of young adults wait only approximately 23 min to be fertilized. One hypothesis is that the foci function to maintain maternal mRNAs in oocytes while fertilization is delayed. In this paper, we examine four gonochoristic rhabditid species: Caenorhabditis remanei, Caenorhabditis sp. CB5161, Caenorhabditis sp. PS1010, and Rhabditella axei DF5006. We demonstrate that in three of these four species, ovulation arrests in unmated females until mating occurs and large cytoplasmic foci develop in arrested oocytes. The oocyte foci contain nuclear pore proteins and, in C. remanei at least, the RNA-binding protein MEX-3 as well as RNA. We speculate that these foci maintain the integrity of ooctyes, possibly maintaining the stability or translational repression of maternal mRNAs in unmated females. We further speculate that their presence in oocytes of old-aged C. elegans hermaphrodites is due to conservation from an ancestral gonochoristic state.