POPULATION GENETICS OF POSTPONED AGING

延迟衰老的人口遗传学

• 批准号: 3746110
• 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/3746110
• 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.

选择推迟衰老的一个混杂因素可能是影响 由于遗传漂变而出现高频的有害基因。 这些有害基因可能会掩盖有益基因的作用 受到自然选择的青睐。 这种近亲繁殖的速度和程度 抑郁症将取决于有效人口规模。 等位基因频率 变异也可能压倒等位基因频率的变化 自然选择（如果人口特别少）或选择 特别薄弱，使得有效人口规模成为关键 范围。 该提案将通过直接估计有效人口规模 衡量男性和女性在以下环境中的生殖成功率 与种群所处的环境相似。这项研究 将提供为数不多的关于男性或女性变异性的详细研究之一 实验室群体中女性生殖成功。 对于可以直接测定的基因频率，复制的研究 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。 这些变化可能会揭示 直接对该基因进行选择或可能反映对连锁基因座的选择 由于连锁不平衡，这影响了等位基因的频率 在相连的中性位点。 在选择推迟的人群中 随着年龄的增长，SOD 上的罕见等位基因急剧增加 轨迹，相对于对照。 为了研究此类连锁基因座，该项目 将测量 SOD 基因和 DNA 之间的连锁不平衡水平 SOD 基因座 10 kb 内不同位置的标记。 比较 复制群体中的连锁不平衡将有助于 区分由单个特有的偶然事件引起的联系 来自事件的人口，比如选择，这对所有人来说都是共同的 人口。 此外，连锁不平衡水平 实验室群体将与自然群体形成对比 作为识别长期实验室后果的一种手段 维持果蝇种群的遗传结构。