Germ Cell Migration in Drosophila

描述(由申请人提供)：发育的许多方面需要单个细胞在不同和复杂的环境中迁移。例如，在脊椎动物胚胎中，神经脊细胞离开发育中的中枢神经系统，长距离迁移，形成感觉神经元、面部软骨和色素细胞等细胞类型。 皮肤。在成人中，迁移细胞类型包括免疫系统细胞、伤口愈合过程中的成纤维细胞和转移过程中的癌细胞。在定向细胞迁移过程中，运动细胞被引导沿着特定的路径，它们识别引导线索并将其转化为定向运动。最后，细胞必须能够识别它们的目标组织并停止迁移，无法到达目标的细胞必须被清除。原始生殖细胞为分析细胞定向迁移提供了一个很好的模型系统。生殖细胞生物学的许多方面，例如它们的整体形态和它们向性腺的体细胞成分奇怪的迁移路径，在整个动物界都是保守的。我们已经用果蝇来识别由胞体产生的引导生殖细胞迁移的信号。我们发现，脂质信号对原始生殖细胞的迁移起着关键作用。这项建议 旨在了解脂质信号和膜成分如何影响生殖细胞的迁移和存活。其目的是表征生殖细胞内的信号过程，并确定引导生殖细胞的细胞外信号的性质和分布。在第一个目标中，我们将使用针对生殖系表达基因的遗传学方法来识别生殖细胞中迁移机制的新的和额外的组件。在第二个目标中，我们将鉴定指导生殖细胞的果蝇磷脂磷酸酶Wunen和Wunen2的脂质靶标，并分析生殖细胞迁移反应的性质及其在生殖细胞生存中的作用。在第三个目标中，我们建议分离一种由体细胞性腺产生的生殖细胞引诱剂，我们已经证明它是由体细胞性腺细胞通过保守的、非常规的ABC转运蛋白进行脂质修饰并输出的。人类生殖细胞的错误迁移被认为是生殖细胞瘤的原因，生殖细胞瘤是在睾丸和卵巢之外发展的生殖系肿瘤。目前尚不清楚是什么原因导致生殖细胞的错误迁移，以及为什么这些明显“丢失”的生殖细胞存活在性腺环境之外。生殖细胞迁移和存活的机制已经在遗传易驯化的生物中进行了研究，如果蝇、老鼠和斑马鱼。这些研究揭示了生殖细胞的行为和控制这一行为的基因有着惊人的相似之处。这一应用的结果可能有助于更好地理解引导生殖细胞迁移的线索和细胞过程，以及在物理上将生殖细胞与体内其他细胞区分开来的线索和细胞过程。

DESCRIPTION (provided by applicant): Many aspects of development require the migration of individual cells through diverse and complex environments. In vertebrate embryos, for example, neural crest cells leave the developing central nervous system and migrate over long distances to give rise to such cell types as sensory neurons, facial cartilage and pigment cells of the skin. In adults, migratory cell types include the cells of the immune system, fibroblasts during wound healing, and cancer cells during metastasis. During directed cell migration, motile cells are guided along a particular path, they recognize guidance cues and translate them into directed movement. Finally, cells must be able to recognize their target tissue and stop migrating and cells that fail to reach their target have to be eliminated. Primordial germ cells provide an excellent model system for the analysis of directed cell migration. Many aspects of germ cell biology, such as their overall morphology and their curious migratory path toward the somatic components of the gonad are conserved throughout the animal kingdom. We have used Drosophila to identify signals produced by the soma that guide migrating germ cells. We find that lipid signaling plays a critical role for migrating primordial germ cells. This proposal aims to understand how lipid signaling and membrane composition affect germ cell migration and survival. The aim is to characterize the signaling processes within the germ cells and to determine the nature and distribution of the extracellular signals that guide germ cells. In the first aim we will use a genetic approach targeted at germline expressed genes to identify new and additional components of the migratory machinery in germ cells. In the second aim, we will characterize the lipid targets of the Drosophila lipidphosphate phosphatases, Wunen and Wunen2 that guide germ cells and analyze the nature of the migratory response in germ cells and its role in germ cell survival. In the third aim, we propose to isolate a germ cell attractant produced by the somatic gonad, which we have shown is lipid modified and exported by the somatic gonad cells by an conserved, unconventional ABC transporter. Mis-migration of germ cells in humans is thought to be the cause of germinomas, tumors of the germ line that develop outside of the testis and ovaries. It remains unclear what causes germ cell mis-migration and why these apparently 'lost' germ cells survive outside of the gonad environment. The mechanisms underlying germ cell migration and survival have been studied in genetically tractable organisms such as Drosophila, mouse and zebrafish. These studies have revealed striking parallels in the behavior of germ cells and in the genes that control this behavior. Findings resulting from this application are likely to contribute to a better understanding of the cues and cellular processes that guide germ cell migration and that physically distinguish germ cells from other cells in the body.