Mouse Mitochondrial DNA Sequences

对野生家鼠种群的基因研究提供了对这些种群结构和动态的洞察。自然遗传变异的知识将增强对实验室小鼠基因组的理解，这是研究许多疾病基础的模型系统。这些知识将有助于理解家鼠种群如此成功的原因，并有助于了解进化的遗传基础。在这个项目中，研究人员将确定线粒体染色体（mtDNA）上基因的核苷酸序列。MtDNA在进化研究中很有用，因为它比核DNA进化得更快。获得的数据将用于估计小鼠mtDNA的进化速度，并将其与已经在人类和其他动物中测量到的速度进行比较。这些理论将被证明，世代时间是分子进化的关键因素，而啮齿动物在分子水平上的进化速度明显快于其他生物。研究结果还将用于进一步研究欧洲杂交区家鼠和小家鼠之间的基因相互作用，并确定与家鼠有亲缘关系和远亲关系的各种啮齿动物之间的进化关系。重点放在解剖和化石数据导致与现有分子证据相冲突的推论的情况下。将采用一种新技术来获得DNA序列。从少量组织中的DNA开始，聚合酶链反应被用来将特定的DNA片段扩增到一百万倍；然后可以直接对扩增产物进行测序。由于这种方法避免了克隆和在成千上万的克隆中寻找所需克隆的繁琐步骤，它使大规模获得DNA序列数据成为可能。对捕获的数百只动物进行DNA序列水平的常规调查，然后在收集一滴血或几根毛发后释放，现在是可行的。此外，由于博物馆皮肤和其他样本中大量存在的修饰DNA痕迹足以作为起始材料，一个多世纪以来积累的世界标本库终于可以进行分子遗传分析了。

Genetical research on wild populations of house mice provides insight into the structure and dynamics of those populations. Knowledge of the natural genetic variation will enhance understanding of the genome of the laboratory mouse, which is a model system for investigating the basis of many diseases. Such knowledge will contribute to understanding what makes house mouse populations so successful and to knowledge of the genetic basis of evolution. In this project, the researchers will determine the nucleotide sequences of genes on the mitochondrial chromosome (mtDNA). MtDNA is of use in evolutionary studies because it evolves more rapidly than nuclear DNA. The data obtained will be used to estimate the rate of mtDNA evolution in mice and to compare it with the rate already measured in humans and other animals. The theories will be tested that generation time is a key factor in molecular evolution and that rodents have evolved significantly faster than other creatures at the molecular level. The results will also be used to investigate further the genetic interactions in the European hybrid zone between Mus domesticus and Mus musculus mice and to determine evolutionary relationships among various rodents closely and distantly related to house mice, with emphasis on cases where anatomical and fossil data have led to inferences in conflict with the available molecular evidence. A new technique will be used to obtain the DNA sequences. Starting with the DNA in a tiny amount of tissue, the polymerase chain reaction is used to amplify specific segments of DNA up to a million-fold; the amplified product can then be sequenced directly. Because this method avoids the tedious steps of cloning and searching for the desired clone among thousands or millions of others, it makes possible obtaining DNA sequence data on a large scale. Routine surveys at the DNA sequence level of hundreds of animals captured and then released after collection of a drop of blood or a few hairs are now feasible. Furthermore, because the traces of modified DNA that abound in museum skins and other samples suffice as the starting material, the world's storehouse of specimens accumulated over a century or more is at last accessible to molecular genetic analysis.