CELL ABLATION USING CRE-MEDIATED DNA RECOMBINATION

通过胚胎干细胞技术操纵小鼠基因组的能力对我们识别哺乳动物胚胎发育所需基因的能力产生了巨大影响。关于建立细胞谱系和组织组织所必需的细胞-细胞相互作用，仍有许多需要了解。我们建议开发一种基于Cre/lox技术的二元转基因系统，用于消融小鼠特定的细胞群。使用这一系统，将有可能通过交配两个表型正常的小鼠品系来生产几乎任何细胞类型的胚胎。有一条线(“通用烧伤子”)有可能在EVES细胞中表达细胞毒素，但除非表达Cre酶，否则不会产生细胞毒素。另一个小鼠品系将在中间中胚层(IM)表达cre基因。通过将这两条线配对，我们将消除IM。这将使我们能够研究IM在小鼠早期胚胎中的功能，并具体检验IM产生肢体诱导剂的假设。这一系统可能有助于分析许多不同组织在调节正常和异常器官生长发育中的功能。

The ability to manipulate the mouse genome via ES cell technology has had a tremendous impact on our ability to identify the genes required for the development of mammalian embryos. Much is still to be understood about the cell-cell interactions necessary to establish cell lineages and to organize tissues. We propose to develop a binary transgenic system based on Cre/lox technology for ablating specific cell populations in mice. Using this system it will be possible to produce embryos with virtually any cell type ablated by mating two phenotypically normal mouse lines. One line (the "universal ablator") will have the potential to express a cytotoxin in eves cell, but cytotoxin will not be produced unless Cre enzyme is expressed. The other mouse line will express the cre gene in the intermediate mesoderm (IM). By mating these two lines, we will eliminate the IM. This will enable us to investigate the function of the IM in the early mouse embryo, and specifically to test the hypothesis that the IM produces the limb inducer. This system will potentially be useful for analyzing the functions of many different tissues in the regulation of normal and abnormal organ growth and development.