GENETIC ANALYSIS OF FGF-5 PROTO-ONCOGENE FUNCTION

FGF-5 原癌基因指定一种分泌性生长因子，具有 与原型成纤维细胞生长因子的序列同源性。 FGF-5。是 在多种胚胎环境、成熟大脑和某些细胞中表达 肿瘤细胞。该应用程序提出了一系列基因实验 以确定 FGF-5 的许多独特功能。我们将破坏一个或 小鼠全能胚胎干 (ES) 中 FGF-5 基因的两个等位基因 细胞通过同源重组。将分析 FGF-5 阴性 ES 细胞 用于体外作为胚状体和作为肿瘤的分化潜力 体内。 FGF-5半合子ES细胞将被注射到囊胚中以衍生 嵌合小鼠并在种系中建立破坏的等位基因。近亲繁殖 将进行以确定 FGF-5 的发育异常 阴性胚胎。我们还将建立携带人类基因的转基因小鼠 FGF-5 基因在发育中的一个子集中表达 特征位点或在某个域中具有结构突变 目前未知的功能。将这些转基因菌株与 FGF-5 交配 半合子小鼠和与半合子品系回交的后代将 产生携带转基因作为唯一功能等位基因的胚胎。的 这些胚胎的异常表型将进一步剖析 FGF-5 的功能。 最后，我们将产生携带人类 FGF-5 转基因的小鼠，该基因突变于 已知可提高 FGF-5 mRNA 翻译效率的位点。这些 小鼠应过度表达 FGF-5 蛋白而无异位表达，并且 由此产生的异常也将有助于确定 FGF-5 的功能。这些老鼠 还应监测癌症倾向。

The FGF-5 proto-oncogene specifies a secreted growth factor which bears sequence homology to the prototypic fibroblast growth factors. FGF-5. is expressed in several embryonic settings, in mature brain, and in some neoplastic cells. This application proposes a series of genetic experiments to determine many of FGF-5's distinct functions. We shall disrupt one or both alleles of the FGF-5 gene in murine totipotent embryonic stem (ES) cells by homologous recombination. FGF-5 negative ES cells will be analyzed for differentiation potential as embryoid bodies in vitro and as tumors in vivo. FGF-5 hemizygous ES cells will be injected into blastocysts to derive chimeric mice and establish a disrupted allele in the germ line. Inbreeding will be performed to determine the developmental abnormalities in FGF-5 negative embryos. We shall also establish transgenic mice bearing human FGF-5 genes which are expressed in a subset of the developmentally characteristic sites or which bear structural mutations in a domain of currently unknown function. Mating these transgenic strains with FGF-5 hemizygous mice and backcrossing progeny with the hemizygous strain will generate embryos carrying the transgenes as sole functional allele. The aberrant phenotypes of these embryos will further dissect FGF-5 function. Lastly, we shall generate mice carrying human FGF-5 transgenes mutated at sites known to increase the translation efficiency of FGF-5 MRNA. These mice should overexpress FGF-5 protein without ectopic expression, and resulting abnormalities will also help determine FGF-5 function. These mice shall also be monitored for cancer predisposition.