Dominance, epistasis and the genetics of postzygotic isolation.
Dominance, epistasis and the genetics of postzygotic isolation.
复制标题
显性、上位性和合子后隔离的遗传学。
DOI：
10.1093/genetics/154.4.1663
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发表时间：
2000
期刊：
影响因子：
3.3
通讯作者：
Orr,HA
中科院分区：
文献类型：
--
作者：
Turelli,M;Orr,HA
物种杂种的不育性和不活力可以用基因座间的“Dobzhansky-Muller”不相容性来解释：当在杂种中聚集在一起时，适合其“正常”遗传背景的等位基因有时会降低适合度。我们提出了一个模型的两个位点的不相容性，区分三种类型的杂交相互作用：杂合基因座之间（H 0），杂合和纯合（或半合子）基因座之间（H1），和纯合基因座之间（H2）。我们通过计算每种类型的不亲和性的预期数量来预测杂交基因型的相对适合度。我们使用这个模型来研究Halfman的规则和大的影响，X染色体的合子后隔离。我们表明，H 0 vs的严重性。H1不相容性是理解Halfton规则的关键，而H1的严重性与H1的严重性相比，H1的严重性与Halfton规则的严重性相比，H1的严重性与Halfton规则的严重性相比。H2不相容性也必须考虑解释大的X效应。在回交分析中，大的X效应并非不可避免，而是像Halfman法则一样，可能经常反映等位基因的隐性，引起合子后隔离。我们还考虑了涉及Y（或W）染色体和母体效应的不相容性。这种不相容性在果蝇物种杂交中很常见，它们在雄性与雌性异配子分类群中的结果可能解释了Halfman规则的例外模式。
The sterility and inviability of species hybrids can be explained by between-locus “Dobzhansky-Muller” incompatibilities: alleles that are fit on their “normal” genetic backgrounds sometimes lower fitness when brought together in hybrids. We present a model of two-locus incompatibilities that distinguishes among three types of hybrid interactions: those between heterozygous loci (H0), those between a heterozygous and a homozygous (or hemizygous) locus (H1), and those between homozygous loci (H2). We predict the relative fitnesses of hybrid genotypes by calculating the expected numbers of each type of incompatibility. We use this model to study Haldane's rule and the large effect of X chromosomes on postzygotic isolation. We show that the severity of H0vs. H1incompatibilities is key to understanding Haldane's rule, while the severity of H1vs. H2incompatibilities must also be considered to explain large X effects. Large X effects are not inevitable in backcross analyses but rather—like Haldane's rule—may often reflect the recessivity of alleles causing postzygotic isolation. We also consider incompatibilities involving the Y (or W) chromosome and maternal effects. Such incompatibilities are common in Drosophila species crosses, and their consequences in male- vs. female-heterogametic taxa may explain the pattern of exceptions to Haldane's rule.