Recombination and the evolution of diploidy.
Recombination and the evolution of diploidy.
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发表时间：
1992-07
期刊：
影响因子：
3.3
通讯作者：
Sarah P. Otto;David Goldstein
中科院分区：
文献类型：
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作者：
Sarah P. Otto;David Goldstein
由于每个基因都有两个拷贝，二倍体生物体能够掩盖隐性有害突变。在本文中，我们提出了一个双位点模型的分析，旨在确定当有害等位基因的掩蔽有利于生物体中的显性二倍体阶段的演变，在单倍体和二倍体阶段之间交替（“世代交替”）。据推测，二倍体将有利于每当掩蔽发生（“掩蔽假说”）。使用分析方法，我们证实，这种掩蔽假设基本上是正确的自由重组：只要杂合表达的有害等位基因是充分掩盖野生型等位基因，二倍体是有利于单倍体。然而，当重组率较低时，二倍体比单倍体更不可能受到青睐。事实上，根据我们的模型，即使掩蔽作用相当强，如果没有显著水平的重组，二倍体的进化也是不可能的。
With two copies of every gene, a diploid organism is able to mask recessive deleterious mutations. In this paper we present the analysis of a two-locus model designed to determine when the masking of deleterious alleles favors the evolution of a dominant diploid phase in organisms that alternate between haploid and diploid phases ("alternation of generations"). It is hypothesized that diploidy will be favored whenever masking occurs ("the masking hypothesis"). Using analytical methods, we confirm that this masking hypothesis is essentially correct under free recombination: as long as the heterozygous expression of deleterious alleles is sufficiently masked by the wild-type allele, diploidy is favored over haploidy. When the rate of recombination is lower, however, diploidy is much less likely to be favored over haploidy. In fact, according to our model, the evolution of diploidy is impossible without significant levels of recombination even when masking is fairly strong.