Regulation of Epithelial Stem Cell Replacement and Follicle Formation in the Drosophila Ovary
Regulation of Epithelial Stem Cell Replacement and Follicle Formation in the Drosophila Ovary
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DOI：
10.1534/genetics.109.109538
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发表时间：
2010-02-01
期刊：
影响因子：
3.3
通讯作者：
Spradling, Allan
中科院分区：
文献类型：
--
作者：
Nystul, Todd;Spradling, Allan
尽管通过对脊椎动物和无脊椎动物系统的卵子发生的研究，我们对卵泡成熟的过程有了很多了解，但对卵泡最初是如何形成的知之甚少。在果蝇中，每个卵巢中的两个体细胞卵泡干细胞（FSCs）产生形成每个卵泡所需的所有极性细胞、柄细胞和主体细胞。我们发现，每个FSC的一个子代形成了大多数卵泡，但细胞类型规格与细胞谱系无关，这与之前声称的早期极性/柄谱系限制相反。相反，关键的细胞间信号开始得很早，并指导细胞行为。来自生殖细胞的初始Notch信号是FSC子代细胞跨越卵巢迁移和偶尔取代相反干细胞所必需的。前后极细胞同时出现在2b区，大约有16个细胞包围囊肿。后来，在出芽期间，茎细胞和额外的极细胞在一个过程中被指定，这个过程经常将后卵泡细胞转移到下一个老卵泡的前表面。这些研究为果蝇卵发生过程中干细胞替代和卵泡形成的机制提供了新的见解。
Though much has been learned about the process of ovarian follicle maturation through studies of oogenesis in both vertebrate and invertebrate systems, less is known about how follicles form initially. In Drosophila, two somatic follicle stem cells (FSCs) in each ovariole give rise to all polar cells, stalk cells, and main body cells needed to form each follicle. We show that one daughter from each FSC founds most follicles but that cell type specification is independent of cell lineage, in contrast to previous claims of an early polar/stalk lineage restriction. Instead, key intercellular signals begin early and guide cell behavior. An initial Notch signal from germ cells is required for FSC daughters to migrate across the ovariole and on occasion to replace the opposite stem cell. Both anterior and posterior polar cells arise in region 2b at a time when similar to 16 cells surround the cyst. Later, during budding, stalk cells and additional polar cells are specified in a process that frequently transfers posterior follicle cells onto the anterior surface of the next older follicle. These studies provide new insight into the mechanisms that underlie stem cell replacement and follicle formation during Drosophila oogenesis.