TARGETED MUTATIONS IN THE ABL TYROSINE KINASE GENE

该提案描述了使用小鼠遗传学工具的实验， 确定c-abl原癌基因的体内功能。c-abl 基因产物是一种对信号很重要的细胞质酪氨酸激酶 转导和控制细胞周期。基因敲除小鼠缺乏c- 上一个供资期间产生的资产负债表显示了一些 表型：围产期致死、发育迟缓、骨异常和缺陷 在早期淋巴细胞谱系中，特别是对凋亡的敏感性， 刺激，这些小鼠的几个遗传研究提出：首先， 将检查由c-abl缺乏引起的骨质疏松症; 将从突变体和对照动物中培养，并对其进行测试。 对一组生长因子的反应能力。第二，新的等位基因c- 通过基因靶向（"敲入"实验）产生ABL。之一 这些等位基因将允许基因的条件性缺失， 在特定的发育时期和特定的组织中;其他人将表达 缺乏特定结构域的c-abl的改变形式。审查这些 小鼠应该有助于确定c- 消融导管第三，育种将用于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abi-2 基因，编码β-相互作用蛋白，和ret-，跨膜 Constantini实验室正在研究的受体激酶。 最后，阿比家族的一个新成员的生殖系突变， 酵母Cdc15基因的哺乳动物同源物，将通过基因 靶向，以及突变单独和与其他敲除一起的作用， 突变将被表征。这些研究应该有助于确定许多 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.