GENETIC ANALYSIS OF FGF-5 PROTO-ONCOGENE FUNCTION

成纤维细胞生长因子-5原癌基因指定了一种分泌的生长因子，它可以 与原型成纤维细胞生长因子的序列同源性。成纤维细胞生长因子-5。是 在几个胚胎环境中，在成熟的大脑中，以及在一些 肿瘤细胞。这项申请提出了一系列基因实验 为了确定成纤维细胞生长因子-5‘S的许多不同功能。我们将扰乱一个或多个 小鼠全能胚胎干细胞中成纤维细胞生长因子-5基因的两个等位基因 细胞通过同源重组。将分析成纤维细胞生长因子-5阴性的ES细胞 体外作为类胚体和肿瘤的分化潜能 活着。将成纤维细胞生长因子-5半合子胚胎干细胞注射到囊胚中，以获得 嵌合小鼠，并在生殖系中建立一个被破坏的等位基因。近亲交配 以确定成纤维细胞生长因子-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 成纤维细胞生长因子-5基因在发育过程中的表达 特征位点或在结构域中具有结构突变的 当前未知功能。将这些转基因菌株与成纤维细胞生长因子-5交配 半合子小鼠及其回交后代将 产生携带转基因作为唯一功能等位基因的胚胎。这个 这些胚胎的异常表型将进一步剖析成纤维细胞生长因子-5的功能。 最后，我们将产生携带人成纤维细胞生长因子-5转基因突变的小鼠。 已知的提高成纤维细胞生长因子-5mRNA的翻译效率的位点。这些 小鼠应该过度表达成纤维细胞生长因子-5蛋白而不是异位表达，并且 由此产生的异常也将有助于确定成纤维细胞生长因子-5的功能。这些老鼠 还应监测癌症的易感性。

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.