FETAL GENE EXPRESSION IN MOUSE SEX DETERMINATION

这个项目的目标是剖析性行为 通过识别新基因确定小鼠的决定/分化途径 在这个途径中，建立它们如何影响每个基因的表达 其他，并通过确定其产品的功能。自.以来 睾丸决定因子基因Sry的发现，至今还很少 了解了它调节哪些其他基因来激活睾丸 分化或抑制卵巢分化，因此 分化的途径在很大程度上仍然是一个谜。因此，我们 建议通过比较mRNAs来寻找这一途径中的新基因 在正常XY男性、正常XX男性胎儿生殖器脊中的表达 注定要变性的雌性和XY胎儿。鼠标 菌株C57BL/6JEi-Y-pos(B6Ypos)将用于产生XY性别 反转的胎儿。这些小鼠携带小鼠的Y染色体 Paschiavinus在C57BL/6J(B6)上的遗传背景和产生XY 雌雄同体的后代(从来不是正常的 男性)。小鼠性反转表型的挽救 肌肉Sry转基因已经证明了Y染色体- 导致性逆转的相关决定因素是睾丸决定 因子基因Sry。11.5天和12.5天时生殖器脊的RNA Coitum(D.P.C.)XX和XY B6小鼠以及XX和XY B6YPOS小鼠 将使用增强型差异显示(EDD)进行比较。对此 现在，已经确定了五个候选的mRNAs。信使RNA 鉴定为处于性别决定/分化途径中 因为它们在男性和女性之间表现出不同的表情 XY性别颠倒的生殖器脊将被用于确定它们的作用 在这条路上。一些新发现的基因的功能将 通过使用ES细胞将零等位基因引入小鼠直接进行测试 基因打靶技术及其对性别表型的影响。 携带性别决定途径基因零等位基因的小鼠将是 用于确定途径中的一个基因如何通过以下方式影响其他基因 检测纯合子空生殖器脊的RNA表达 性别决定途径mRNAs。很可能是纯合子突变 其中一些基因会产生部分性逆转表型(AS 在一些XY B6Ypos小鼠中可以看到)。在这些情况下，小鼠将被培育出来 携带一个以上性别决定无效等位基因的组合 为了建立这些基因在植物体内的功能关系 路径。

The goals of this project are to dissect the sex determination/differentiation pathway of mice by identifying new genes in this pathway, establishing how they influence the expression of each other, and by determining the functions of their products. Since the discovery of the testis-determining factor gene Sry, little has been learned about which other genes it regulates to activate testis differentiation or repress ovarian differentiation, and thus this pathway of differentiation still remains largely a mystery. We thus propose to search for new genes in this pathway by comparing mRNAs expressed in genital ridges from fetuses of normal XY males, normal XX females and XY fetuses that are destined to be sex reversed. The mouse strain C57BL/6JEi-Y-pos(B6Ypos) will be used to generate XY sex reversed fetuses. These mice carry the Y chromosome from Mus poschiavinus on the C57BL/6J(B6) genetic background and produce XY offspring that are either hermaphrodites or females (never normal males). Furthermore, rescue of the sex reversal phenotype with a Mus musculus Sry transgene has demonstrated that the Y-chromosome- associated determinant causing sex reversal is the testis-determining factor gene Sry. RNAs from genital ridges at 11.5 and 12.5 days post coitum (d.p.c.) from XX and XY B6 mice and from XX and XY B6YPOS mice will be compared using enhanced differential display (EDD). At this time, five candidate mRNAs have been identified. Messenger RNAs identified as being in the sex determination/differentiation pathway because they show differences in expression between male and female and XY sex reversed genital ridges will be pursued to establish their roles in the pathway. The function of some of the newly identified genes will be tested directly by introducing null alleles into mice using ES cell gene targeting technology and determining the effect on sex phenotype. Mice carrying null alleles of sex determination pathway genes will be used to determine how one gene in the pathway influences others by assaying RNA of homozygous null genital ridges for expression of other sex determination pathway mRNAs. It is likely that homozygous mutants of some of these genes will produce partial sex reversal phenotypes (as seen in some of the XY B6Ypos mice). In these cases mice will be bred that carry combinations of more than one sex determination null allele to establish the functional relationships of these genes in the pathway.