Genetic Analysis of Snail Superfamily Genes in Mice

这项提案的长期目标是了解蜗牛超家族基因在人类发育过程中所起的作用。 哺乳动物的胚胎发育Snail超家族基因编码含锌指的DNA结合 作为转录抑制因子的蛋白质。这个超家族有两个主要分支：蜗牛家族和 Scratch家族脊椎动物中蜗牛超家族的每个分支都有两个成员：蜗牛和蛞蝓。 Snail家族，以及Scratch家族的Seratch 1和Scratch 2。我们一直在研究蜗牛基因 家族成员Sna和Slug，并构建和分析了这两种基因的靶向无效突变， 基因. SNA纯合子突变胚胎在原肠胚形成期间死亡，表现出上皮细胞的缺陷， 中胚层的产生所需的间充质转化。蛞蝓纯合子突变小鼠是可以存活的， 但显示出生长迟缓和各种其它缺陷。然而，许多问题仍然存在， Sna基因在原肠胚形成后发生的发育事件中所起的作用，或者Snail是否 超家族基因Sbch 1和Sbch 2在胚胎发生过程中起重要作用。 在这个建议中，分子和遗传方法将被用来检查蜗牛的作用， 超家族基因在小鼠胚胎发生过程中发挥作用。本提案的具体目标是：1）构建 Sna基因功能等位基因的条件性丧失和获得，以分析其在原肠胚形成后的作用 2）检验脊椎动物Snail和Slug基因的作用已经被证实的假设。 在从鱼类、两栖动物和鸟类进化到哺乳动物的过程中， 3）构建并分析Snail基因的靶向无效突变 超家族基因Sna ch 1和Sna ch 2; 4）检查Sna基因在发育中的作用， 滋养层细胞谱系; 5）使用微阵列鉴定Sna蛋白的下游转录靶标 Sna突变细胞系和胚胎的分析，DNA结合位点的计算机分析，以及DNA结合 问题研究这些研究将进一步加深我们对蜗牛超家族基因在人类发育过程中所起作用的理解。 哺乳动物的发育，并将与正常和异常人类发育的研究有关。

The long-term goal of this proposal is to understand the roles that Snail superfamily genes play during embryonic development in mammals. Snail superfamily genes encode zinc finger-containing DNA binding proteins that act as transcriptional repressors. This superfamily has two main branches: the Snail family and the Scratch family. Each branch of the Snail superfamily in vertebrates has two members: Snail and Slug for the Snail family, and Seratchl and Scratch2 for the Scratch family. We have been studying the Snail gene family members Sna and Slug, and have constructed and analyzed targeted null mutations of both of these genes. Sna homozygous mutant embryos die during gastrulation, exhibiting defects in the epithelial- mesenchymal transition required for generation of the mesoderm. Slug homozygous mutant mice are viable, but show growth retardation and various other defects. However, many questions remain about the possible roles played by the Sna gene in developmental events occurring after gastrulation, or whether the Snail superfamily genes Scratchl and Scratch2 play essential roles during embryogenesis. In this proposal, both molecular and genetic approaches will be utilized to examine the roles that Snail superfamily genes play during embryogenesis in mice. The specific aims of this proposal are: 1) Construct conditional loss and gain of function alleles of the Sna gene to analyze its role during postgastrulation developmental stages; 2) Test the hypothesis that the roles of the vertebrate Snail and Slug genes have been interchanged during evolution from fish, amphibians and birds to mammals by constructing a knock-in allele of the Slug cDNA into the Sna locus; 3) Construct and analyze targeted null mutations of the Snail superfamily genes Scratch1 and Scratch2; 4) Examine the role of the Sna gene in development of the trophoblast cell lineage; 5) Identify downstream transcriptional targets of the Sna protein using microarray analysis of Sna mutant cell lines and embryos, in silico analysis of DNA binding sites, and DNA binding studies. These studies will further our understanding of the roles played by Snail superfamily genes during mammalian development, and will be relevant to the study of both normal and abnormal human development.