Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University, Beer-Sheva 84105, Israel.
Development. 2011 Nov;138(21):4661-71. doi: 10.1242/dev.069161.
Asymmetrical localization of mRNA transcripts during Drosophila oogenesis determines the anteroposterior and dorsoventral axes of the Drosophila embryo. Correct localization of these mRNAs requires both microtubule (MT) and actin networks. In this study, we have identified a novel gene, CG43162, that regulates mRNA localization during oogenesis and also affects bristle development. We also showed that the Drosophila gene javelin-like, which was identified based on its bristle phenotype, is an allele of the CG43162 gene. We demonstrated that female mutants for jvl produce ventralized eggs owing to the defects in the localization and translation of gurken mRNA during mid-oogenesis. Mutations in jvl also affect oskar and bicoid mRNA localization. Analysis of cytoskeleton organization in the mutants reveal defects in both MT and actin networks. We showed that Jvl protein colocalizes with MT network in Schneider cells, in mammalian cells and in the Drosophila oocyte. Both in the oocyte and in the bristle cells, the protein localizes to a region where MT minus-ends are enriched. Jvl physically interacts with SpnF and is required for its localization. We found that overexpression of Jvl in the germline affects MT-dependent processes: oocyte growth and oocyte nucleus anchoring. Thus, our results show that we have identified a novel MT-associated protein that affects mRNA localization in the oocyte by regulating MT organization.
在果蝇卵子发生过程中，mRNA 转录本的不对称定位决定了果蝇胚胎的前后轴和背腹轴。这些 mRNA 的正确定位需要微管（MT）和肌动蛋白网络。在这项研究中，我们鉴定了一个新的基因 CG43162，它调节卵子发生过程中的 mRNA 定位，也影响刚毛的发育。我们还表明，基于刚毛表型鉴定的果蝇基因 javelin-like 是 CG43162 基因的一个等位基因。我们表明，jvl 雌性突变体由于 gurken mRNA 在卵子发生中期定位和翻译的缺陷而产生腹侧化的卵子。jvl 突变也影响 Oskar 和 bicoid mRNA 的定位。对突变体细胞骨架组织的分析显示 MT 和肌动蛋白网络都存在缺陷。我们表明 Jvl 蛋白在 Schneider 细胞、哺乳动物细胞和果蝇卵母细胞中与 MT 网络共定位。在卵母细胞和刚毛细胞中，该蛋白定位于 MT 负端富集的区域。Jvl 与 SpnF 相互作用，并需要其定位。我们发现 Jvl 在生殖细胞中的过表达会影响 MT 依赖性过程：卵母细胞生长和卵母细胞核锚定。因此，我们的结果表明，我们已经鉴定了一种新的 MT 相关蛋白，它通过调节 MT 组织影响卵母细胞中的 mRNA 定位。
