Comparative evolutionary genetics of spontaneous mutations affecting fitness in rhabditid nematodes
Comparative evolutionary genetics of spontaneous mutations affecting fitness in rhabditid nematodes
复制标题
DOI：
10.1073/pnas.0406056102
复制
发表时间：
2005-04-19
影响因子：
11.1
通讯作者：
Lynch, M
中科院分区：
文献类型：
--
作者：
Baer, CF;Shaw, F;Lynch, M
有害突变对生物体生物学的各个方面都具有根本的重要性。进化遗传学家已经花费了巨大的努力来估计全基因组的突变率和新突变对适应性的影响，但是基因组突变特性在分类群内和分类群之间的变化程度在很大程度上是未知的，特别是在多细胞生物中。从两个高度近交系的线虫家族中的三个物种的每一个小杆线虫科（Caushabditis briggsae，Caushabditis elegans，和Oscheius myriophila），我们允许突变积累在相对缺乏自然选择的200代。我们的文件显着的变化，因为菌株之间和物种之间的新突变的衰减速度的健身。每代突变衰减的健身估计是非常一致的菌株之间的测定相隔100代。适合度的突变衰减率与基因组突变率呈正相关，与平均突变效应呈负相关。这些结果提供了明确的实验证据突变的全基因组性质的实质性变化内和物种之间，并加强从以前的实验中的结论，新的突变的健身的累积效应可以显着不同的相关类群。
Deleterious mutations are of fundamental importance to all aspects of organismal biology. Evolutionary geneticists have expended tremendous effort to estimate the genome-wide rate of mutation and the effects of new mutations on fitness, but the degree to which genomic mutational properties vary within and between taxa is largely unknown, particularly in multicellular organisms. Beginning with two highly inbred strains from each of three species in the nematode family Rhabditidae (Caenorhabditis briggsae, Caenorhabditis elegans, and Oscheius myriophila), we allowed mutations to accumulate in the relative absence of natural selection for 200 generations. We document significant variation in the rate of decay of fitness because of new mutations between strains and between species. Estimates of the per-generation mutational decay of fitness were very consistent within strains between assays 100 generations apart. Rate of mutational decay in fitness was positively associated with genomic mutation rate and negatively associated with average mutational effect. These results provide unambiguous experimental evidence for substantial variation in genome-wide properties of mutation both within and between species and reinforce conclusions from previous experiments that the cumulative effects on fitness of new mutations can differ markedly among related taxa.