Formation, architecture and polarity of female germline cyst in Xenopus
Formation, architecture and polarity of female germline cyst in Xenopus
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DOI：
10.1016/j.ydbio.2003.10.002
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发表时间：
2004-02-01
影响因子：
2.7
通讯作者：
Etkin, LD
中科院分区：
文献类型：
--
作者：
Kloc, M;Bilinski, S;Etkin, LD
脊椎动物生殖细胞包囊的形成及包囊内卵母细胞的分化过程尚不清楚。在大多数无脊椎动物中，在配子发生的初始阶段，雄性和雌性生殖细胞完全同步发育为相互连接的细胞的合胞体，称为生殖细胞囊（簇，巢）。利用电子显微镜，免疫染色和三维重建，我们能够阐明的过程中，在发育中的脊椎动物非洲爪蟾卵巢囊肿的形成。我们发现非洲爪蟾的生殖细胞包囊含有16个细胞，这些细胞在一般结构和分子组成上与果蝇包囊相似。巢细胞通过含有环形通道样结构的细胞质桥连接。巢细胞含有类似于果蝇融合体的结构，其可能参与中心粒的锚定和围绕中心粒的初级线粒体云（PMC）的组织。我们还发现，与其他生物体相比，在非洲爪蟾，细胞凋亡是一个罕见的事件在发展中的卵巢。我们的研究表明，在无脊椎动物和脊椎动物中，负责雌性生殖细胞包囊形成和生殖细胞极性建立的过程是高度保守的。果蝇和非洲爪蟾之间的差异以及各自系统的独特性可能是通过对生殖细胞胞囊相同的基本设计进行修改而进化的。(C)2003年爱思唯尔公司All rights reserved.
Little is known about the formation of germline cyst and the differentiation of oocyte within the cyst in vertebrates. In the majority of invertebrates in the initial stages of gametogenesis, male and female germ cells develop in full synchrony as a syncytia of interconnected cells called germline cysts (clusters, nests). Using electron microscopy, immunostaining and three-dimensional reconstruction, we were able to elucidate the process of cyst formation in the developing ovary of the vertebrate Xenopus laevis. We found that the germline cyst in Xenopus contains 16 cells that are similar in general architecture and molecular composition to the cyst in Drosophila. Nest cells are connected by cytoplasmic bridges that contain ring canal-like structures. The nest cells contain a structure similar to the Drosophila fusome that that is probably involved in anchoring of the centrioles and organization of the primary mitochondrial cloud (PMC) around the centriole. We also find that in contrast to other organisms, in Xenopus, apoptosis is a rare event within the developing ovary. Our studies indicate that the processes responsible for the formation of female germline cysts and the establishment of germ cell polarity are highly conserved between invertebrates and vertebrates. The dissimilarities between Drosophila and Xenopus and the uniqueness of each system probably evolved through modifications of the same fundamental design of the germline cyst. (C) 2003 Elsevier Inc. All rights reserved.