CONSTRAINTS ON MOLECULAR VARIATION AND EVOLUTION

分子变异和进化的限制

• 批准号: 6240585
• 负责人: Martin E KREITMAN
• 金额: $ 16.27万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-01-01 至 1998-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6240585
• 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.

该提案的目的是研究遗传施加的约束 位置以及通过分子进化和变化的交配系统。 这应该阐明变异和进化的基本机制。 对这些知识对于对人类的理解具有重要意义 遗传疾病。 第一个项目将确定X-的相对进化速率 果蝇中的染色体和常染色体基因座。 理论和间接 经验证据表明，自适应评估率可能是 X连锁基因的速度比可比较的常染色体基因更快。 理论 表明这两个类别的中性进化是相同的，但是 替代略微有害等位基因的速度应较慢 用于X连锁基因座。 这些预测将通过比较速率来测试 合适的同义和非同义核苷酸取代 果蝇种类中的基因座，其中携带这些基因座的常剂体 已易位到X染色体上，物种的速率 基因座是常染色体。 在第二个项目中，繁殖系统对 分子变异将通过检查DNA序列变异来研究 在黄铜植物的种类中 而其他人则完全浮出水面。 理论预测 高度自我应导致几乎完全失去多样性 将通过比较同义词的模式来测试中性站点 两类物种的变化。 可能的行动 在维护变化方面的选择将通过比较同义词来测试 两种类型的物种内部和之间的非义词变化与非同义变化。