WILD DERIVED GENETIC VARIATION

描述：（改编自提案）假常染色体区（PAR） 有几个特点，使其成为一个独特的重要 区域学习。它是X和Y染色体配对的区域 在减数分裂过程中，所产生的交叉仅限于一个区域， 大约1%的X染色体因此，1 cM等于53 kbp 而在雌性减数分裂中的1cM等于480 kbp， 染色体区域第二，PAR与X染色体相邻 但这一区域的基因似乎逃脱了 失活。逃逸是否是边界的性质 性染色体和PAR之间的联系，或者这些基因的功能， 还有待确定。第三，X-Y配对对于 完成减数分裂和雄性育性。X-Y配对失败， 由X或Y染色体上的区域缺失引起 或种间X和Y染色体的异源组合 杂种雄性导致减数分裂在MI时停止。私家侦探具有 开发了大量的关键资源， 并获得了重要的克隆探针，以开始 物理分析该提案描述了一系列实验性 旨在扩展PAR的遗传和物理分析， 特别感兴趣的是确定的分子遗传基础， X-Y配对的失败，以及由此产生的减数分裂停滞。私家侦探也 建议检查X染色体遗传学的远端， 物理图来定义PAR和分子的边界 防止X染色体失活扩散到这些基因的元件。在 第二组目标，P.I.提出了进一步发展和 维护野生小鼠资源， 基因分析的机会。 具体目标是：1）开发一套菌株或种特异性 PAR的分子探针并表征分子特征 基因组DNA中的探针。这些克隆的探针将用于 遗传和物理分析PAR。2)识别限制 标记的PAR和恢复这些序列作为探针进行分析。 3)目的分析中国人远侧X染色体遗传图谱和物理图谱， 不同的小鼠物种，以确定进化模式， 从X到假常染色体区域的保守性和分歧。 4)利用PAR遗传标记追踪X-Y分离 亚种间和种间杂种雄性的配对表型， 确定这个特征是否是由分散的序列决定的 PAR或特定基因座是否负责。 野生小鼠资源的开发和维护：1） 保持和重新衍生的不同小鼠物种是独一无二的，我们的 殖民地2)利用Mus维护和开发特殊资源 特殊材料。

DESCRIPTION: (Adapted from Proposal) The pseudoautosomal region (PAR) of mammals has several features that make it an uniquely important region for study. It is the region of the X and Y chromosome that pairs during meiosis with a resultant crossover that is confined to a region of about 1% of the X chromosome. As a consequence, one cM equals 53 kbp whereas one cM in female meiosis equals 480 kbp for the identical chromosome region. Second, the PAR is contiguous with X chromosomes that undergo inactivation, but the genes in this region appear to escape from inactivation. Whether the escape is a property of the boundary between the sex chromosome and the PAR, or a function of these genes, remains to be determined. Third, X-Y pairing is essential for completion of meiosis and male fertility. A failure of X-Y pairing that results from either a deletion of the region from the X or Y chromosome or a heterologous combination of X and Y chromosomes in interspecific hybrid males leads to an arrest of meiosis at MI. The P.I. has developed a large array of crucial resources for genetically analyzing this region and has obtained important cloned probes to begin the physical analysis. This proposal describes a series of experimental aims to extend the genetic and physical analysis of the PAR with specific interest in identifying the molecular genetic basis for the failure of X-Y pairing, and the resultant meiotic arrest. The P.I. also proposes to examine the distal end of the X chromosome genetic and physical maps to define the boundary of the PAR and the molecular elements that prevent the spread of X inactivation to these genes. In a second group of aims, the P.I. proposes the further development and maintenance of wild-derived mouse resources that will extend and refine the opportunities for genetic analysis. The specific aims are: 1) To develop a set of strain or species specific molecular probes for the PAR and to characterize the molecular features of these probes in genomic DNA. These cloned probes will be used to genetically and physically analyze the PAR. 2) To identify restriction landmarks in the PAR and recover these sequences as probes for analysis. 3) To analyze the distal X chromosome genetic and physical maps of different Mus species to determine the evolutionary patterns of conservation and divergence from the X to the pseudoautosomal regions. 4) To use the PAR genetic markers to follow the segregation of the X-Y pairing phenotype in intersubspecific and interspecific hybrid males to determine whether this trait is determined by dispersed sequences across the PAR or whether a specific locus is responsible. Development and Maintenance of Wild-derived Mouse Resources: 1) To maintain and re-derive the diverse Mus species that are unique to our colony. 2) To maintain and develop special resources using the Mus special materials.