Ultrastructural characterization of spermatogenesis and its evolutionary conservation in the germline: Germinal granules in mammals
Ultrastructural characterization of spermatogenesis and its evolutionary conservation in the germline: Germinal granules in mammals
复制标题
DOI：
10.1016/j.mce.2008.11.009
复制
发表时间：
2009-07-10
影响因子：
4.1
通讯作者：
Nakatsuji, Norio
中科院分区：
文献类型：
--
作者：
Chuma, Shinichiro;Hosokawa, Mihoko;Nakatsuji, Norio
许多动物的生殖细胞具有称为生殖颗粒或细胞质的特征性细胞质结构。生发颗粒是缺乏限制膜的核糖核蛋白（RNP）无定形聚集体，其分子组成在不同物种中进化上保守。果蝇、线虫和爪蟾等模式动物的germinal颗粒研究。主要集中在早期胚胎发生过程中结构对预期生殖细胞的不对称分配。另一方面，在哺乳动物中，在生殖细胞分化的后期阶段，如精子发生和卵子发生中，germinal颗粒变得可辨别。有趣的是，最近的遗传学研究表明，小鼠的生殖颗粒成分主要在雄性出生后的生殖细胞分化中起作用，但在早期胚胎阶段不起作用。尽管不同物种和种系的不同分化阶段所共有的胚粒的功能仍然难以捉摸，但越来越多的证据表明，特征性RNP与RNA代谢、逆转录转座子调节以及与线粒体的相互作用有关。在这里，我们提出了一个简短的概述哺乳动物germinal颗粒的结构和分子特征。(C)2008爱思唯尔爱尔兰有限公司保留所有权利。
Germline cells of many animals possess characteristic cytoplasmic structures termed germinal granules or nuage. Germinal granules are ribonucleoprotein (RNP) amorphous aggregates lacking limiting membranes, and their molecular composition is evolutionarily conserved in divergent species. Studies on germinal granules in several model animals, such as Drosophila, C elegans and Xenopus. have mainly focused on the asymmetric partitioning of the structures to prospective germ cells during early embryogenesis. In mammals, on the other hand, germinal granules become discernible at later stages of germ cell differentiation, such as in spermatogenesis and oogenesis. Interestingly, recent genetic studies indicate that germinal granule components in mice function primarily in postnatal germ cell differentiation in the male, but not in early embryonic stages. While the function(s) of germinal granules shared by divergent species and at different differentiation stages of the germline remain elusive, evidence is accumulating that the characteristic RNP is associated with RNA metabolism, retrotransposon regulation and interplay with mitochondria. Here, we present a brief overview of the structural and molecular characteristics of mammalian germinal granules. (C) 2008 Elsevier Ireland Ltd. All rights reserved.