Self-dependence of the Mutation Rate

突变率的自相关性

• 批准号: 0717167
• 负责人: Charles Baer
• 金额: $ 48.67万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-11-01 至 2012-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0717167&HistoricalAwards=false
• 关键词: Self; dependence; Mutation; Rate

The goal is to determine whether the rate at which heritable mutations occur in an organism's genome depends on the number of mutations that are already present. It was previously demonstrated that different stocks of nematodes in which mutations accumulated for 200 generations experienced different rates of decline in reproductive rate ("fitness"). The process will be repeated for a further 135 generations on a subset of these stocks with high and low fitness. If the mutation rate depends on the current mutational status, low fitness stocks will decline more rapidly than high fitness stocks. A complication is that the effect of a mutation on fitness may depend on the number of mutations already present, whereby the cumulative effects of mutations do not equal the sum of the individual effects. To distinguish between the two possibilities, the genomes of representative stocks will be sequenced, directly establishing the relationship between current mutational status and future mutation rate. The mutation rate is usually considered a fixed property of a species, but if the mutation rate depends on the number of mutations already present, there are important consequences for conservation biology, agriculture, and medicine. For example, a temporary increase in the level of a mutagenic pollutant in the environment could have lasting effects on the mutation rate even after the pollutant was removed from the environment. Understanding the relationship between current and future mutational status will enable prediction of the future consequences of environmental factors that increase the mutation load in the short term.

目标是确定生物体基因组中发生遗传突变的速率是否取决于已经存在的突变数量。 先前证明，其中突变累积了200代的线虫的不同种群经历了不同的繁殖率（“适合度”）下降速率。 这个过程将重复135代以上的一个子集，这些股票具有高和低的健身。 如果突变率取决于当前的突变状态，则低适应性股票将比高适应性股票下降得更快。 一个复杂的问题是，突变对适应性的影响可能取决于已经存在的突变数量，因此突变的累积效应不等于个体效应的总和。 为了区分这两种可能性，将对代表性种群的基因组进行测序，直接建立当前突变状态与未来突变率之间的关系。突变率通常被认为是物种的固定属性，但如果突变率取决于已经存在的突变数量，则对保护生物学，农业和医学有重要影响。 例如，环境中致突变污染物水平的暂时增加可能对突变率产生持久影响，即使在污染物从环境中移除之后。 了解当前和未来突变状态之间的关系将能够预测短期内增加突变负荷的环境因素的未来后果。