GENE AND TRANSGENE REGULATION IN THE DEVELOPING MOUSE

哺乳动物分化和肿瘤发生的分子遗传学研究 转基因小鼠该项目包括几种方法，其中一些 与其他实验室合作。 1.胚胎透镜的肿瘤发生。胚胎期的透镜泡 一个明确的纤维分化程序，从妊娠中期开始， 最终形成半透明的成人透镜 结构我们已经靶向了大肿瘤抗原的表达， 将DNA病毒多瘤病毒和SV 40转移到发育中的透镜上， 了解这些致癌基因产物如何干扰有序的过程 透镜的区别。多瘤T抗原可以永生化， 转化透镜细胞。碱性成纤维细胞可部分消除其作用 生长因子和胰岛素，与正常 透镜差异。相比之下，SV 40 T抗原导致透镜肿瘤。 肿瘤进展的速率在个体线之间是不同的。 转基因小鼠，似乎与分化状态有关 在胚胎透镜中T抗原积累时获得。的 因此，用两种病毒肿瘤抗原获得的结果强调了 分化中的细胞作为癌基因产物的场所的重要性 与细胞生长调节剂竞争细胞周期的控制 以及生物体的命运岌岌可危的地方。的可用性 永生化的透镜细胞使我们能够克隆和表征一个基因， 它指定了一个与晶状体特异性调节有关的因素， 晶状体蛋白表达。 2.通过同源重组进行基因打靶。这方面的目的是 该项目的目的是改变小鼠的固有染色体基因， 表征所得突变体表型。在技术上， 要求实验步骤的顺序，野生型基因序列， 在多能胚胎干（ES）细胞中通过插入突变的 序列在其位置。突变的胚胎干细胞被注射到胚泡中 它被转移到一个养母身上， 可以繁殖突变性状的嵌合体。我们已经建立了这个 技术在实验室中，目前针对c-fos 原癌基因此外，我们还参加了旨在 产生高雪氏病的小鼠模型，高雪氏病是一种人类疾病， 葡萄糖脑苷脂酶基因的确定突变。

Molecular genetics of mammalian differentiation and oncogenesis studied in transgenic mice. The project comprises several approaches, some of them reflecting collaborations with other laboratories. 1. Oncogenesis of the embryonic lens. The embryonic lens vesicle undergoes a well defined fiber differentiation program, starting at mid gestation, that ultimately results in the formation of the translucent adult lens structure. We have targeted the expression of the large tumor antigens of the DNA viruses polyoma and SV40 to the developing lens in an effort to understand how these oncogene products interfere with the orderly process of lens differentiation. The polyoma T antigen immortalizes but does not transform lens cells. Its action is partly abrogated by basic fibroblast growth factor and by insulin, factors that have been implicated in normal lens differentiation. By contrast, the SV40 T antigen causes lens tumors. The rate of tumor progression differs between individual lines of transgenic mice and appears to be linked to the state of differentiation attained in the embryonic lens at the time of T antigen accumulation. The results obtained with the two viral tumor antigens thus underscore the importance of the differentiating cell as the site where oncogene products compete with regulators of cell growth for the control of the cell cycle and where the fate of the organism is at stake. The availability of immortalized lens cells has enabled us to clone and characterize a gene that specifies a factor implicated in the regulation of lens-specific crystallin expression. 2. Gene targeting by homologous recombination. The purpose of this aspect of the project is to alter resident chromosomal genes of the mouse and to characterize the resulting mutant phenotypes. Following a technically demanding sequence of experimental steps, a wild type gene sequence is replaced in a pluripotent embryonic stem (ES) cell by inserting a mutated sequence in its place. The mutant ES cell is injected into a blastocyst which is transferred into a foster mother in an effort to obtain germ line chimeras that can propagate the mutant trait. We have established this technique in the laboratory and are presently targeting the c-fos proto-oncogene. In addition, we have joined collaborative efforts aimed at generating a mouse model of Gaucher's disease, a human disorder based on defined mutations of the glucocerebrosidase gene.