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的影响。关于建立细胞系和组织所必需的细胞-细胞相互作用，仍有许多有待了解。我们建议建立一个基于Cre/lox技术的二元转基因系统，用于小鼠特异性细胞群的消融。使用这一系统，将有可能产生胚胎几乎任何细胞类型消融交配两个表型正常的小鼠系。一条线（“通用烧蚀器”）将有可能在每个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。另一个小鼠系将在中胚层（IM）表达cre基因。通过配对这两条线，我们将消除IM。这将使我们能够研究早期小鼠胚胎中IM的功能，特别是验证IM产生肢体诱导剂的假设。该系统将潜在地用于分析许多不同组织在正常和异常器官生长发育的调节中的功能。

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.