TARGETED MUTATIONS IN THE ABL TYROSINE KINASE GENE

这项建议描述了使用小鼠遗传学工具进行的实验 确定c-abl原癌基因的体内功能。C-ABL 基因产物是一种胞质酪氨酸激酶，对信号有重要作用 细胞周期的转导和控制。C-缺乏基因敲除小鼠 在上一次供资期间产生的资产负债表显示了一些 表型：围产期致死性、跑步、骨骼异常和缺陷 在早期淋巴样细胞谱系中，特别是对凋亡的敏感性 刺激，提出了对这些小鼠的几项遗传学研究：第一， 将检查由c-abl缺乏引起的骨质疏松症；成骨细胞 将从突变的和对照的动物中培养出来，并测试它们的 对一系列增长因素做出反应的能力。第二，c-基因的新等位基因 ABL将通过基因打靶(“敲入”实验)产生。其中之一 这些等位基因将允许有条件地删除该基因 在发育和选定的组织中选定的时间；其他人将表达 C-abl的变形形式缺少特定的结构域。对这些问题的审查 小鼠应该能帮助确定从c-C-1产生的每条通路的功能。 ABL.第三，将利用育种来产生缺乏的复合突变小鼠 C-ABL和其他具有相关功能的基因，包括ABI-1和-2 编码Abl相互作用蛋白的基因，以及一种跨膜蛋白ret- 康斯坦蒂尼实验室正在研究受体激酶。 最后，Abi家族一个新成员的胚系突变 酵母CDC15基因的哺乳动物同源物，将由基因产生 靶向，以及单独突变和其他基因敲除的影响 突变将被描述为特征。这些研究应该有助于定义许多 C-abl在哺乳动物发育和生理中的多种功能。

This proposal describes experiments using the tools of mouse genetics to determine the in vivo functions of the c-abl proto-oncogene. The c-abl gene product is a cytoplasmic tyrosine kinase important for signal transduction and control of the cell cycle. Knock-out mice deficient in c- abl, generated in the previous funding period, exhibit a number of phenotypes: perinatal lethality, runting, bone abnormalities, and defects in early lymphoid cell lineages, notably a sensitivity to apoptotic stimuli, Several genetic studies of these mice are proposed: First, the osteoporosis causes by the c-abl deficiency will be examined; osteoblasts will be cultured from mutant and control animals, and tested for their ability to respond to a panel of growth factors. Second, new alleles of c- abl will be generated by gene targeting ("knock-in" experiments). One of these alleles will permit the conditional deletions of the gene at selected times in development and in selected tissues; others will express altered forms of c-abl lacking particular domains. Examination of these mice should help determine the functions of each pathway emanating from c- abl. Third, breeding will be used to generate compound mutant mice lacking c-abl and other genes with related functions, including the abi-1 and -2 genes, encoding Abl-interacting proteins, and ret-, a transmembrane receptor kinase under investigation by the Constantini laboratory. Finally, a germ-line mutation of a new member of the Abi family, a mammalian homologue of the yeast Cdc15 gene, will be generate by gene targeting, and the effects of the mutation alone and with other knock-out mutations will be characterize. These studies should help define the many diverse functions of c-abl in mammalian development and physiology.