Regulation of Vertebrate Gonad Formation by Fibroblast Growth Factor Signaling

 描述（由申请人提供）：成纤维细胞生长因子（Fgf）信号传导与上皮性卵巢癌的进展有关，并且许多Fgf配体及其受体（Fgfr）在发育和成年脊椎动物性腺中表达。然而，FGF信号传导在正常性腺发育或功能中的作用仅在有限的背景下被定义。我们的长期目标是确定FGF信号在性腺发育，病理生理学，从而生育，特别是在卵巢中的作用。本申请的目的是确定FGF信号传导在早期性腺原基发育中的作用。我们的切入点是在斑马鱼的FGF配体编码基因的突变，结果n快速损失的生殖细胞在体细胞性腺原基形成的阶段。我们的中心假设是，FGF信号是必需的早期体细胞性腺的发展和体细胞性腺缺陷在我们的FGF突变体导致继发性生殖细胞的损失。该假设是根据申请人实验室的初步数据制定的。我们将通过追求以下三个具体目标来测试该假设：1）表征用于性腺原基发育的FGF信号传导的空间需求; 2）确定FGF信号传导在调节早期性腺发育中的作用;和3）确定早期斑马鱼性腺发育所需的FGF受体。基于我们强有力的初步数据，我们假设FGF配体是由早期性腺原基的体细胞产生的。在第一个目标下，我们将使用遗传镶嵌分析来确定在哪些细胞中产生Fgf配体。在第二个目标中，我们将通过定义我们的FGF突变体中的发育缺陷来定义FGF配体在性腺原基发育中起什么作用。我们将使用组织学，标记基因分析和转录谱的组合来测试我们的假设，即FGF信号促进和/或维持指定早期体细胞性腺命运的基因的表达。根据我们的第三个目标，我们将通过确定同源FGF受体来确定哪些细胞响应于FGF配体。这将使我们能够确定FGF信号调节早期性腺发育的机制。我们将使用Fgf受体的功能丧失，或在必要时，条件突变，以确定哪些是早期性腺发育所需的。拟议的研究是创新的，因为它利用了一个独特的FGF突变体，使我们能够确定一个新的作用，FGF信号在早期性腺发育中的遗传顺从的斑马鱼系统。这项拟议的研究意义重大，因为它将定义一种调节早期性腺发育的分子途径，因此可能确定FGF信号传导缺陷如何解释其他健康女性中不明病因的不孕或卵巢早衰病例，以及FGF信号传导在性腺起源癌症中的作用。

 DESCRIPTION (provided by applicant): Fibroblast growth factors (Fgf) signaling has been implicated in the progression of epithelial ovarian cancer, and numerous Fgf ligands and their receptors (Fgfr) are expressed in the developing and adult vertebrate gonads. However, the role of Fgf signaling in normal gonad development or function has only been defined in a limited context. Our long-term goal is to determine the roles Fgf signaling plays in gonad development, pathophysiology, and thus fertility, especially in the ovary. The objective of this application is o define the role Fgf signaling plays in the development of the early gonad primordium. Our entry point is the identification of a mutation in an Fgf ligand-encoding gene in zebrafish that results n rapid loss of germ cells during a stage when the somatic gonad primordium is forming. Our central hypothesis is that Fgf signaling is required for development of the early somatic gonad and that a somatic gonad defect in our Fgf mutant leads secondarily to loss of germ cells. This hypothesis has been formulated based on preliminary data from the applicant's laboratory. We will test this hypothesis by pursuing the following three Specific Aims: 1) Characterize the spatia requirement of Fgf signaling for development of the gonad primordium; 2) Determine the role of Fgf signaling in regulating the development of the early gonad; and 3) Determine which Fgf receptor(s) is required for development of the early zebrafish gonad. Based on our strong preliminary data, we hypothesize that the Fgf ligand is produced by the somatic cells of the early gonad primordium. Under the first aim we will determine in what cells the Fgf ligand is produced using genetic mosaic analysis. In the second aim, we will define what role the Fgf ligand plays in development of the gonad primordium by defining the developmental defect in our Fgf mutant. We will use a combination of histology, marker gene analysis and transcriptional profiling to test our hypothesis that Fgf signals promote and/or maintain the expression of genes that specify the early somatic gonad fate. Under our third aim we will define which cells respond to the Fgf ligand by determining the cognate Fgf receptor. This will allow us to define the mechanism by which Fgf signaling regulates early gonad development. We will use of loss-of-function, or when necessary, conditional mutations, in Fgf receptors to determine which are required for development of the early gonad. The proposed research is innovative because it utilizes a unique Fgf mutant that has enabled us to identify a novel role for Fgf signaling in early gonad development in the genetically amenable zebrafish system. The proposed research is significant because it will define a molecular pathway that regulates the development of the early gonad, and therefore is likely to identify how defects in Fgf signaling can account for cases of infertiliy or premature ovarian failure of unknown etiology in otherwise healthy women, and the role of Fgf signaling in gonad-originating cancers.