CONSTRAINTS ON MOLECULAR VARIATION AND EVOLUTION

分子变异和进化的限制

• 批准号: 6107687
• 负责人: Martin E KREITMAN
• 金额: --
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-01-01 至 1998-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6107687
• 关键词: Drosophilidae; alleles; angiosperms; animal genetic material tag; animal population genetics; autosomal dominant trait; autosome; biochemical evolution; chromosome translocation; complementary DNA; gene frequency; gene mutation; genetic markers; genetic polymorphism; genetic recombination; heterozygote; inbreeding; molecular cloning; natural selections; nucleic acid sequence; plant population genetics; protein sequence; sex chromosomes; sex linked trait; species difference

The aim of this proposal is to study the constraints imposed by genetic location and by the mating system on molecular evolution and variation. This should illuminate basic mechanisms of variation and evolution. Knowledge of these is of significance for the understanding of human genetic disease. The first project will determine the relative rates of evolution of X- chromosomal and autosomal loci in Drosophila. Theory and indirect empirical evidence suggest that the rate of adaptive evaluate may be faster for X-linked genes than for comparable autosomal genes. Theory shows that the of neutral evolution is the same for the two classes, but the rate of substitution of slightly deleterious alleles should be slower for X-linked loci. These predictions will be tested by comparing rates of synonymous and non-synonymous nucleotide substitutions at suitable loci in a species of Drosophila in which autosome carrying these loci have been translocated onto the X-chromosome with rates in species in which the loci are autosomal. In the second project, the effect of breeding system on the level of molecular variation will be studied by examining DNA sequence variation in species of Brassicaceous plants, some of which highly self-fertilizing and others of which are completely outcrossing. Theoretical predictions the high selfing should lead to an almost complete loss of diversity at neutral sites will be tested by comparing patterns of synonymous variation in the two classes of species. The possible action of selection in maintaining variation will be tested by comparing synonymous versus non-synonym variation within and between the two types of species.

这项建议的目的是研究遗传学所施加的限制， 位置和由交配系统对分子进化和变异的影响。 这应该阐明变异和进化的基本机制。 了解这些对于理解人类的行为具有重要意义 遗传病 第一个项目将确定X的相对进化速率， 染色体和常染色体基因座。 理论和间接 经验证据表明，适应性评价的比率可能是 X连锁基因比可比较的常染色体基因更快。 理论 这表明，中性进化的两个类是相同的，但 轻微有害等位基因的替换速率应该较慢 对于X连锁基因座。 这些预测将通过比较 同义和非同义核苷酸取代在合适的 携带这些基因座的常染色体 已转移到X染色体上，在物种中的比例为 基因座是常染色体的 在第二个项目中，研究了育种系统对玉米产量水平的影响。 通过检测DNA序列变异来研究分子变异 在菊科植物的种类中，其中一些高度自交 而另一些则是完全异交的。 理论预测 高度自交会导致几乎完全丧失多样性， 中性网站将通过比较同义模式进行测试， 两类物种的差异。 的可能作用 通过比较同义词， 与两种类型物种内部和之间的非同义变异相比。