Mosaic analysis in the drosophila ovary reveals a common hedgehog-inducible precursor stage for stalk and polar cells.
Mosaic analysis in the drosophila ovary reveals a common hedgehog-inducible precursor stage for stalk and polar cells.
复制标题
果蝇卵巢中的镶嵌分析揭示了茎细胞和极细胞的常见刺猬诱导前体阶段。
DOI：
10.1093/genetics/151.2.739
复制
发表时间：
1999
期刊：
影响因子：
3.3
通讯作者：
Ruohola-Baker,H
中科院分区：
文献类型：
--
作者：
Tworoger,M;Larkin,MK;Bryant,Z;Ruohola-Baker,H
卵巢卵泡细胞的两个小亚群的命运似乎是相关的：Notch、Delta、fs(1)Yb 或刺猬蛋白的突变同时导致柄细胞和极细胞的规格缺陷。这两个亚群都是在生殖细胞中决定的，并且都在卵子发生早期停止分裂。为了测试这些亚群通过谱系相关的可能性，我们在卵巢中产生了显性标记的有丝分裂克隆。茎细胞和极细胞中的小限制克隆被发现彼此相邻，其频率太高而无法通过独立诱导来解释。因此，我们提出了一种模型，其中柄细胞和极细胞源自与其他滤泡细胞的前体不同的前体群体。我们通过影响茎和极细胞形成的突变体的表征来支持和扩展该模型。我们发现 Hedgehog 的异位表达可以诱导极细胞和茎细胞的命运，大概是通过作用于前体阶段。相反，我们发现失速既不影响前体细胞的诱导，也不影响茎细胞和极细胞命运之间的决定，而是影响茎细胞的一些后期分化步骤。此外，我们发现异位极性细胞和柄细胞扰乱了下面卵母细胞的前后极性。
The fates of two small subgroups of the ovarian follicle cells appear to be linked: mutations in Notch, Delta, fs(1)Yb, or hedgehog cause simultaneous defects in the specification of stalk cells and polar cells. Both of these subgroups are determined in the germarium, and both cease division early in oogenesis. To test the possibility that these subgroups are related by lineage, we generated dominantly marked mitotic clones in ovaries. Small, restricted clones in stalk cells and polar cells were found adjacent to each other at a frequency much too high to be explained by independent induction. We therefore propose a model in which stalk cells and polar cells are derived from a precursor population that is distinct from the precursors for other follicle cells. We support and extend this model by characterization of mutants that affect stalk and polar cell formation. We find that ectopic expression of Hedgehog can induce both polar and stalk cell fate, presumably by acting on the precursor stage. In contrast, we find that stall affects neither the induction of the precursors nor the decision between the stalk cell and polar cell fate but, rather, some later differentiation step of stalk cells. In addition, we show that ectopic polar and stalk cells disturb the anterior-posterior polarity of the underlying oocyte.