GENETIC CONTROL OF MESODERM AND NEURAL CREST FORMATION

描述(改编自调查人员摘要)：的长期目标 这项建议是为了了解分子和遗传机制 早期调控细胞迁移和上皮-间充质转化 移植后的小鼠胚胎。在这项提案中，这些问题将是 通过构建和分析基因的目标零突变进行研究 SNA和鼻涕虫。这些基因是果蝇基因蜗牛的老鼠同源物， 它编码锌指蛋白，这是合子所需的 果蝇胚胎发育过程中中胚层的形成。蜗牛的分析 其他脊椎动物中的同源基因表明蜗牛家族基因是重要的 在调节细胞之间的黏附相互作用中，例如相互作用 参与上皮细胞向间充质细胞的转化 中胚层和神经脊的生成。的具体目标 这一建议是：1)检验SNA和Slug基因是 对于正常的胚胎发育是必不可少的，而纯合子的胚胎 这些基因的零突变会表现出分层缺陷和 中胚层、顶层内胚层和神经脊等组织的迁移， 通过产生和鉴定包含这些零突变的小鼠 基因。2)通过以下方式评估SNA和鼻涕虫突变表型的细胞自主性 构建SNA和Slug突变型纯合子胚胎干细胞系 等位基因，并分析这些细胞在嵌合胚胎中的行为。3) 确定小鼠的SNA和Slug基因是否具有部分功能 通过构建和分析SNA/Slug双突变体来实现冗余。4) 重组SNA和鼻涕虫DNA结合位点特异性的测定 蛋白质，并产生针对这些蛋白质的抗体。5)克隆 蜗牛基因家族的其他成员，并描述了他们的特征 在野生型胚胎和SNA和鼻涕虫突变胚胎中均有表达。

DESCRIPTION (adapted from investigator's abstract): The long term goal of this proposal is to understand the molecular and genetic mechanisms that regulate cell migration and epithelial-mesenchymal transitions in early postimplantation mouse embryos. In this proposal, these questions will be studied by constructing and analyzing targeted null mutations of the genes sna and slug. These genes are mouse homologs of the Drosophila gene snail, which encodes a zinc finger protein that is required zygotically for mesoderm formation during Drosophila embryogenesis. Analysis of snail homologs in other vertebrates suggests that snail family genes are important in regulating adhesive interactions between cells, such as the interactions involved in the epithelial-mesenchymal transition required for the generation of both the mesoderm and the neural crest. The specific aims of this proposal are: 1) Test the hypothesis that the sna and slug genes are essential for normal embryonic development, and that embryos homozygous for null mutations of these genes will show defects in delamination and migration of tissues such as mesoderm, parietal endoderm and neural crest, by generating and characterizing mice containing null mutations in these genes. 2) Assess the cell autonomy of sna and slug mutant phenotypes by constructing embryonic stem cell lines homozygous for sna and slug mutant alleles, and analyzing the behavior of these cells in chimeric embryos. 3) Determine whether the sna and slug genes in mice are in part functionally redundant by constructing and analyzing sna/slug double mutants. 4) Determine the DNA binding site specificity of recombinant SNA and SLUG proteins, and generate antibodies specific for these proteins. 5) Clone additional members of the snail gene family, and characterize their expression in both wild type embryos and in sna and slug mutant embryos.