Gene-based polymorphisms reveal limited genomic divergence in a species with a heritable life-history dimorphism.
Gene-based polymorphisms reveal limited genomic divergence in a species with a heritable life-history dimorphism.
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基于基因的多态性揭示了具有可遗传的生活史二态性的物种中有限的基因组差异。
DOI：
10.1111/ede.12128
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发表时间：
2015
影响因子：
2.9
通讯作者：
Rockman,MatthewV
中科院分区：
文献类型：
--
作者：
Zakas,Christina;Rockman,MatthewV
了解生活史特征的遗传基础是进化生物学的一个长期目标。许多密切相关的物种有着截然不同的生活史策略，这表明导致不同生活史的早期发育转变迅速而频繁地进化。起源于早期发育的生活史变化对物种的形态，生态，遗传多样性甚至物种形成率都有深远的下游影响。这种发育模式的转变是如何发生的，其潜在的遗传结构是什么？为了开始，以解决这些问题，我们调查了遗传变异的一个新兴的模型在发展演变，多毛类Streblospio benedicti，它有两个对比和高度遗传的后代类型。我们比较了两种发育模式个体的基于转录本的SNP基因型，以确定它们之间的基因组分化程度。我们发现，有广泛的等位基因共享两种类型，和最小的固定差异。我们使用网站频谱，以适应人口模型，我们的数据，并确定有最近的基因流之间的发展形态。我们的数据表明，遗传发育二型性的进化与长期的遗传隔离或基因组广泛的分歧无关。相反，发育重要基因座的差异，或许多基因座的适度等位基因频率差异，可能是造成剧烈生活史差异的原因。
Understanding the genetic basis of life‐history traits is a long‐standing goal of evolutionary biology. Many closely related species have contrasting life‐history strategies, suggesting that the switches in early development that lead to divergent life‐histories evolve quickly and frequently. Life‐history changes that originate in early development have profound downstream effects on a species' morphology, ecology, genetic diversity, and even speciation rate. How do such transitions in development mode occur, and what is the underlying genetic architecture? To begin to address these questions, we investigated genetic variation in an emerging model in developmental evolution, the polychaeteStreblospio benedicti,which has two contrasting and highly heritable offspring types. We compare transcript‐based SNP genotypes of individuals of the two development modes to determine the extent of genomic differentiation between them. We find that there is extensive allele sharing across the two types, and minimal fixed differences. We use the site frequency spectrum to fit demographic models to our data and determine that there is recent gene flow between developmental morphs. Our data suggest that the evolution of a genetic developmental dimorphism is not associated with longstanding genetic isolation or genomically extensive divergence. Rather, differences at developmentally important loci, or modest allele‐frequency differences at many loci, may be responsible for the drastic life‐history differences.