Identifying the mechanistic role of the Wunens during germ cell migration

描述（由申请人提供）：细胞迁移描述细胞定向移动到体内特定位置。这个过程是组织形成和多细胞生物体发育的重要步骤。此外，细胞迁移是维持身体免疫系统和伤口愈合所必需的。细胞迁移的中断可能导致诸如血管疾病和癌症进展等医学问题。果蝇（Drosophilamelanogastor）的生殖细胞经历了一个刻板的和遗传调节的迁移过程，因此为研究细胞迁移提供了一个理想的模型系统。遗传学研究已经确定了一个保守的脂质磷酸磷酸酶（LPPs）家族，Wunens，作为果蝇胚胎生殖细胞迁移的重要调节因子。Wunens作为生殖细胞排斥剂起作用，并且是引导生殖细胞沿着沿着适当的路线到达胚胎性腺所必需的。在体细胞如中肠和中枢神经系统中缺乏Wunen功能的情况下，生殖细胞迁移是异常的，生殖细胞分散在整个胚胎中。此外，Wunen功能是生殖细胞生存和适当迁移所必需的。与其他LPP类似，Wunens被认为通过细胞外磷脂底物的去磷酸化来发挥作用。然而，Wunens调控生殖细胞迁移的机制还不清楚。本提案的目的是确定和描述这些机制。我们推测，Wunens水解和摄取分泌的磷脂，作为一种化学引诱剂和调节膜动力学所需的生殖细胞迁移和生存。体细胞中的局部Wunen活动产生磷脂梯度，指导生殖细胞向发育中的性腺适当迁移。为了解决这个问题，首先将通过细胞分选技术从胚胎中分离生殖细胞，使我们能够在简化的环境中研究它们。分选的生殖细胞将用于离体迁移测定，使我们能够概括Wunen化学排斥活性并鉴定具有化学引诱物活性的Wunen调节的磷脂。Wunen在生殖细胞膜动力学中的作用将通过缺乏Wunen功能的分选细胞的详细表型分析来确定。最后，Wunen介导的脂质摄取的机制将通过基于细胞的筛选来阐明该过程的其他介质。进一步的研究将集中在这些基因预测有作用的调节膜动力学。总之，这些数据将提供深入了解的机制，脂质调节促进一个重要的细胞迁移过程。

DESCRIPTION (provided by applicant): Cell migration describes the directed movement of cells to a particular location in the body. This process is an essential step in tissue formation and the development of multicellular organisms. Furthermore, cell migration is required for maintenance of the body's immune system and wound healing. Disruptions in cell migration can lead to medical problems such as vascular disease and the progression of cancer. The germ cells of the fruit fly, Drosophila melanogastor, undergo a stereotypic and genetically regulated migration process and thus provide an ideal model system to study cell migration. Genetic studies have identified a conserved family of lipid phosphate phosphatases (LPPs), the Wunens, as important regulators of germ cell migration in the Drosophila embryo. The Wunens function as germ cell repellents and are required for directing germ cells along a proper route to the embryonic gonad. In the absence of Wunen function in somatic cells such as the midgut and central nervous system, germ cell migration is abnormal with germ cells found scattered throughout the embryo. Furthermore, Wunen function is required within the germ cells for survival and proper migration. Similar to other LPPs, the Wunens are thought to function by dephosphorylation of extracellular phospholipid substrates. However, the mechanisms by which Wunens regulate germ cell migration are not well understood. The goal of this proposal is to identify and characterize these mechanisms. We hypothesize that Wunens hydrolyze and uptake a secreted phospholipid which acts as a chemoattractant and regulator of membrane dynamics required for germ cell migration and survival. Localized Wunen activity in somatic cells creates a phospholipid gradient, directing the proper migration of germ cells to the developing gonad. To address this model, germ cells will first be isolated from the embryo by cell sorting techniques, allowing us to study them in a simplified environment. Sorted germ cells will utilized in an ex vivo migration assay, allowing us to recapitulate Wunen chemorepellent activity and identify Wunen-regulated phospholipids with chemoattractant activity. The role of Wunen in germ cell membrane dynamics will be determined by a detailed phenotypic analysis of sorted cells lacking Wunen function. Finally, the mechanism of Wunen-mediated lipid uptake will be clarified by a cell-based screen for additional mediators of this process. Further studies will be focused on those genes predicted to have roles in the regulation of membrane dynamics. Taken together, these data will provide insight to the mechanisms by which lipid regulation promotes an essential cell migration process.