POPULATION GENETICS OF POSTPONED AGING

延迟衰老的人口遗传学

• 批准号: 3768445
• 负责人: LAURENCE D MUELLER
• 金额: --
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3768445
• 关键词: DNA; Drosophilidae; aging; alleles; animal breeding; animal population genetics; chromosome walking; evolution; gender difference; gene frequency; genetic markers; genetic models; genetic polymorphism; genome; growth media; linkage mapping; longevity; molecular genetics; nucleic acid sequence; phenotype; polymerase chain reaction; reproduction; sex behavior; statistics /biometry; superoxide dismutase

A confounding factor in selection for postponed aging may be the influence of deleterious genes which rise to high frequency due to genetic drift. Such deleterious genes could obscure the effects of beneficial genes favored by natural selection. The rate and magnitude of such inbreeding depression will depend on the effective population size. Allele frequency variation may also overwhelm the changes in allele frequencies produced by natural selection if the population is particularly small or selection particularly weak, making the effective population size a critical parameter. This proposal will estimate effective population size by direct measurement of male and female reproductive success in environments that are similar to those that the populations are maintained in. This research will provide one of the few detailed studies of the variability of male or female reproductive success in laboratory populations. For gene frequencies which can be assayed directly, the study of replicated laboratory populations can reveal changes in allele frequencies which are associated with particular selection regimes. Such changes may reveal selection directly on that gene or may reflect selection on a linked locus which has, due to linkage disequilibrium, affected the frequency of alleles at the linked neutral locus. In the populations selected for postponed aging, there has been a dramatic increase in a rare allele at the SOD locus, relative to the controls. To study such linked loci, this project would measure levels of linkage disequilibrium between the SOD gene and DNA markers at various positions within 10 kb of the SOD locus. Comparisons of linkage disequilibrium in the replicate populations will aid in distinguishing linkage arising from chance events peculiar to a single population from events, like selection, which should be common to all populations. In addition, the levels of linkage disequilibrium in the laboratory populations would be contrasted to that of a natural population as a means of identifying the consequences of prolonged laboratory maintenance on the genetic structure of Drosophila populations.

选择推迟衰老的混杂因素可能是影响 由于遗传漂移而导致高频的有害基因。 这种有害基因可能掩盖有益基因的影响 受到自然选择的青睐。 这种近交的速率和幅度 抑郁症将取决于有效的人口规模。 等位基因频率 变化也可能不堪重负 自然选择如果人口特别小或选择 特别弱，使有效的人口规模成为关键 范围。 该提案将通过直接估算有效的人口规模 测量男性和女性在环境中的生殖成功 与人口所维持的人相似。这项研究 将提供有关男性变异性或 女性在实验室人群中的生殖成功。 对于可以直接测定的基因频率，重复的研究 实验室人群可以揭示等位基因频率的变化 与特定的选择制度相关。 这样的变化可能会揭示 直接在该基因上选择或可能反映在链接基因座上的选择 由于连锁不平衡，它影响了等位基因的频率 在链接的中性基因座。 在选择推迟的人群中 衰老，草皮处的稀有等位基因急剧增加 基因座，相对于控件。 为了研究这种链接的基因座，这个项目 将测量SOD基因和DNA之间的连锁不平衡水平 在SOD基因座10 kb之内的各个位置的标记。 比较 重复人群中的连锁不平衡将有助于 区分单个偶然事件引起的联系 事件中的人口，例如选择，这应该是所有人共有的 人群。 另外，连锁的水平不平衡 实验室人口将与自然人口形成鲜明对比 作为确定延长实验室后果的一种手段 维持果蝇种群的遗传结构。