Surprising Fitness Consequences of GC-Biased Gene Conversion. II. Heterosis
Surprising Fitness Consequences of GC-Biased Gene Conversion. II. Heterosis
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DOI：
10.1534/genetics.110.120808
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发表时间：
2011-01-01
期刊：
影响因子：
3.3
通讯作者：
Glemin, Sylvain
中科院分区：
文献类型：
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作者：
Glemin, Sylvain
杂种优势是一种普遍存在的现象，它对应于来自不同群体或品系的个体相对于其亲本杂交后适合度的增加。自世纪初以来，其遗传基础一直是一个有争议的话题。杂种中隐性有害突变的掩盖可能解释了杂种优势的很大一部分。因此，这些突变的动力学和后果已被深入研究。最近，有人提出，GC偏向基因转换（gBGC）可能会强烈影响有害突变的命运，并可能有显着的健身后果。gBGC是模拟有利于G和C等位基因的选择的重组相关过程，其可以干扰选择，例如通过增加GC有害突变的频率。通过分析gBGC和选择在细分群体中的相互作用，研究了gBGC如何影响杂种优势的数量和遗传结构。为此，我分析了无限岛模型的数值计算和解析近似。结果表明，gBGC对杂种优势总量的影响不大，但对杂种优势的遗传基础有很大影响。
Heterosis is a widespread phenomenon corresponding to the increase in fitness following crosses between individuals from different populations or lines relative to their parents. Its genetic basis has been a topic of controversy since the early 20th century. The masking of recessive deleterious mutations in hybrids likely explains a substantial part of heterosis. The dynamics and consequences of these mutations have thus been studied in depth. Recently, it was suggested that GC-biased gene conversion (gBGC) might strongly affect the fate of deleterious mutations and may have significant fitness consequences. gBGC is a recombination-associated process mimicking selection in favor of G and C alleles, which can interfere with selection, for instance by increasing the frequency of GC deleterious mutations. I investigated how gBGC could affect the amount and genetic structure of heterosis through an analysis of the interaction between gBGC and selection in subdivided populations. To do so, I analyzed the infinite island model both by numerical computations and by analytical approximations. I showed that gBGC might have little impact on the total amount of heterosis but could greatly affect its genetic basis.