EXPRESSION/FUNCTION OF C FOS AND C JUN IN DEVELOPMENT

这项提议的目标是研究原癌基因的作用。 在正常的哺乳动物发育中，并理解如何在 这些基因的表达可能会导致妊娠浪费或先天性 畸形。C-fos和c-jun原癌基因共同发挥作用 在分子水平上调节基因表达，已被选为 这项研究认为原癌基因与发育有关。C-FOS是 在胚胎发育过程中以组织特异性的方式表达，并显示出高 胚胎外组织中的表达水平。这些纸巾起到了 在胚胎着床和胚胎存活过程中的重要作用 栽植后时期。我们的假设是组织特异性 表达反映了c-fos基因产物的功能需求。我们 进一步假设c-jun将以类似的方式表达，并将 在开发过程中也是必需的。 这项提案的具体目的是澄清c-fos的范围和 C-jun基因在移植前和移植后早期的表达 并检测这些基因在发育过程中的功能作用。 这将通过以下具体目标实现：具体目标一。 我们将详细介绍c-fos和c-jun在Pre-Pre和 应用RNA原位杂交法研究小鼠移植后发育 蛋白质定位和免疫组织化学定位。 具体目标2.培育胚胎干细胞系 同源基因打靶对c-fos和c-jun基因突变的杂合性研究 重组。靶向c-fos的初步结果已经成功 现在已经有了一个突变的克隆人。具体目标3.届时我们将 为突变的C-fos或产生杂合和纯合的转基因动物 C-jun通过ES细胞嵌合体的方式，以确定一种 低剂量或缺乏c-fos或c-jun基因产物对发育的影响。一 一系列嵌合体已经被试验繁殖，以产生杂合子小鼠。 如果我们确定杂合子细胞不能完成 嵌合体中的配子发生，一种替代的救援方案将被使用 这将使研究杂合子男性的配子发生成为可能。

The goals of this proposal are to investigate the role of proto-oncogenes in normal mammalian development and to understand how aberrations in the expression of these genes could result in pregnancy wastage or congenital malformations. C-fos and c-jun proto-oncogenes function together to regulate gene expression at the molecular level and have been chosen for this study as proto-oncogenes implicated in development. C-fos is expressed in a tissue-specific manner during embryogenesis and shows high levels of expression in extraembryonic tissues. These tissues play an essential role in implantation and in the survival of the embryo during the postimplantation period. It is our hypothesis that tissue-specific expression reflects a functional requirement for the c-fos gene product. We further postulate that c-jun will be expressed in a similar manner and will also be required during development. The specific aims of this proposal are to clarify the extent of c-fos and c-jun expression throughout the pre- and early postimplantation period in the mouse and examine the functional role of these genes in development. This will be accomplished by the following specific aims: Specific Aim I. We will detail the expression of c-fos and c-jun during pre- and postimplantation mouse development using in situ hybridization for RNA localization and immunohistochemistry for localization of the proteins. Specific Aim 2. We will produce embryonic stem (ES) cell lines heterozygous for mutated c-fos and c-jun by gene targeting via homologous recombination. Preliminary results have been successful in targeting c-fos and one mutated clone is now available. Specific Aim 3. We will then produce transgenic animals heterozygous and homozygous for mutated C-fos or c-jun by way of ES cell chimeras, in order to determine the effect of a lower dose or absence of c-fos or c-jun gene product on development. One series of chimeras is already being test-bred to produce heterozygous mice. If we determine that heterozygous cells are not capable of completing gametogenesis in a chimera, an alternative, rescue protocol will be used that will allow the study of gametogenesis in heterozygous males.