GENE-TRAP APPROACHES TO MAMMALIAN DEVELOPMENT

对小鼠早期发育中的事件如原肠胚形成和 体轴的形成极大地有助于隔离 影响这些过程的突变和其产物可以 调节这些发育事件。 寻求更多的发展 重要的基因将通过结合联合收割机和突变的方法来辅助， 和分子分析。 其中一种方法涉及“基因- 诱捕”报告载体到小鼠胚胎干细胞中。 这些载体 仅当整合到所述载体中时才允许报告基因表达。 宿主基因的转录单位。 忠实反映的整合 宿主基因表达，破坏宿主基因，并使其容易分子 克隆，可以通过报告基因在体外或体内表达来预选。 嵌合体 该提案的目的是1）完成分子和 突变体分析40个已分离的整合细胞系 在原肠胚形成周围具有空间限制性表达; 2）携带 对其中一种进行了详细的分子和胚胎学分析， 一种积分，其表达式仅限于结点和头进程 3）进行基因陷阱插入的体外筛选 其在用生长因子bFGF处理后表现出改变的表达。 这些研究应该提供相当多的关于新基因的信息 参与了小鼠胚胎的形成， 人类先天性出生缺陷和遗传性疾病的个体发生。

The study of events in early mouse development such as gastrulation and formation of the body axis have been greatly assisted by isolation of both mutations affecting such processes and genes whose products could regulate these developmental events. The search for more developmentally important genes would be aided by approaches that combine both mutational and molecular analysis. One such approach involves integration of "gene- trap" reporter vectors into mouse embryonic stem cells. These vectors only allow expression of the reporter gene when integrated within the transcription unit of a host gene. Integrations that faithfully reflect host gene expression, disrupt the host gene and allow its easy molecular cloning, can be preselected by reporter gene expression in vitro or in chimeras. The aims of this proposal are 1) to complete the molecular and mutant analysis of c. 40 already isolated cell lines with integrations that have spatially restricted expression around gastrulation; 2) carry out a detailed molecular and embryological analysis of one such integration whose expression is confined to the node and head process derivatives; 3) carry out an in vitro screen for gene trap insertions that show altered expression after treatment with the growth factor bFGF. These studies should provide considerable information on novel genes involved in patterning the mouse embryo and give insights into the ontogeny of human congenital birth defects and genetic diseases.