GENETICS OF HYBRID STERILITY IN DROSOPHILA

这个项目的目的是为了了解遗传基础 杂种育性分析在分子水平上的物种形成 男性。核心问题是是否存在主效基因 果蝇种间杂交导致雄性完全不育 如果是这样的话，这些基因是如何在分子水平上被描述的呢？ 水平。我们建议将X染色体的小片段从 通过重复的方法将毛管拟青霉或拟青霉转化到拟青霉基因组中 回交。介绍将首先通过以下几个子集进行识别 九个可见的标记，然后是一系列X连锁的DNA克隆。 1.消耗臭氧层物质基因的精细定位和分子克隆--我们有 证明了造成杂交雄性不育的一个主要因素，ods。 在16DE中，我们有22个交叉点的500kb的间隔 (附录1)。我们建议将一个字母内的正式文件系统划分为 使用基于来自于 宇宙克隆人。10-20多条交叉点为 然后，通过在以下位置执行PCR-SSCP来筛选此更精细的间隔 两侧的两个DNA位点中的任何一个。重叠的克隆覆盖 整个字母间隔将被隔离。我们的目标是在 20KB。 2-3。ODS-Light的细胞学、分子生物学和进一步的遗传分析 显微镜和二维蛋白质凝胶电泳会 已执行。在准确绘制消耗臭氧层物质地图时，进行文字记录分析， 最终，将进行种系转化。遗传 与邻近基因的相互作用，D。 将分析模拟物和EMS诱导的突变。 4.Y-Rb-NP-区不育性的完整分析 来自毛叶石杉和石杉的引种将被携带 出去。对这第二个地区的分析将同样广泛和 详细说明了消耗臭氧层物质的基因，包括遗传学、细胞学和 分子特征。 5.与np-v-m-g标记区域相关的不育性将是 以字母分割的分辨率通过粗略映射来描绘。什么时候 所有拟议的实验都完成了，80%的X染色体将 已经进行了分析。 6.分析Y染色体对杂种不育性的影响。 将拟态石杉的5条Y染色体分别导入两条染色体 兄弟种，反过来，从毛叶盘藻到拟盘盘藻 (附录5、6)。这将是对该角色最全面的分析 Y染色体在杂交种雄性不育中的作用

The objective of this project is to understand the genetic basis of speciation at the molecular level by analyzing the sterility in hybrid males. The central questions is whether there exist major genes that cause complete male sterility in the interspecific hybrids of Drosophila and, if they do, how these genes can be characterized at the molecular level. We proposed to introgress small segments of the X chromosome from D. mauritiana or D. sechellia into the genome of D. simulans by repeated backcrossing. The introgressions will be identified fist by a subset of nine visible markers and then by a series of X-linked DNA clones. 1. Fine mapping and molecular cloning of the Ods gene-We have demonstrated that a major factor for hybrid male sterility, Ods, exists in 16DE, a 500kb interval within which we have 22 crossover points (Appendix 1). We propose to demarcate Ods within a letter division by using the PCR-SSCP analysis based on the primer sequences derived from cosmic clones. 10-20 more introgression lines with a crossover point in this finer interval will then be screened by performing PCR-SSCP at either of the two flanking DNA sites. Overlapping clones covering the whole letter interval will be isolated. The goal is to define Ods within 20kb. 2-3. Cytological, molecular and further genetic analysis of Ods-Light microscopy and 2- dimensional protein gel electrophoresis will be performed. When Ods is accurately mapped, transcript analysis and, eventually, germ line transformation will be carried out. Genetic interactions with neighboring genes, polymorphic suppressor in D. simulans and EMS-induced mutations will be analyzed. 4. A complete analysis of the sterility of the y-rb-np-region introgressed from both D. mauritiana and D. sechellia will be carried out. The analyses of this second region will be as extensive and detailed as those for the Ods genes, including genetic, cytological and molecular characterizations. 5. The sterility associated with the region marked by np-v-m-g will be delineated by coarse mapping at the resolution of letter divisions. When all the proposed experiments are completed, 80% of the X chromosome will have been analyzed. 6. We will analyses the effect of Y chromosome on hybrid sterility by introgressing each of 5 Y chromosomes from D. simulans into the two sibling species and, reciprocally, from D. mauritiana into D. simulans (Appendix 5,6). It will be the most comprehensive analysis of the role of Y chromosome in the sterility of hybrid males.