Genomic divergence during speciation driven by adaptation to altitude.
Genomic divergence during speciation driven by adaptation to altitude.
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DOI：
10.1093/molbev/mst168
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发表时间：
2013-12
影响因子：
10.7
通讯作者：
Filatov DA
中科院分区：
文献类型：
--
作者：
Chapman MA;Hiscock SJ;Filatov DA
尽管达尔文的《物种起源》暗示选择是物种形成的主要驱动力，但人们对自然选择在物种形成中的作用仍然知之甚少。特别是，目前还不清楚少数基因的选择如何导致全基因组的分歧和不同物种的形成。我们使用了一个特别有吸引力的明确的情况下，最近的植物生态物种形成的人口和基因组基础的物种形成驱动的适应对比条件。高海拔千里光和低海拔千里光。chalcifolius生活在山的山坡上的极端。埃特纳，西西里，并形成一个混合区，在中间海拔高度，但保持形态独特。这些物种的遗传分化进行了分析，在DNA多态性和基因表达水平的高通量测序转录组从多个人。在分析的18,000个基因中，只有一小部分（90个）在两个物种之间显示出差异表达。这些基因表现出显着升高的物种分化（FST和Dxy），与多样化的选择作用于这些基因。该物种的全基因组遗传分化令人惊讶地低（FST = 0.19），而200个基因显示出显着较高的（错误发现率< 1%;平均离群值FST > 0.6）种间分化和局部适应的证据。尽管基因流动不断，但仅在少数位点进行多样化选择可能足以形成和维持分类学上定义明确的物种。这就解释了为什么许多密切相关的物种（特别是植物）尽管进行了杂交，但在表型和生态学上仍然不同，这是一个长期困扰自然学家和遗传学家的问题。
Even though Darwin’s “On the Origin of Species” implied selection being the main driver of species formation, the role of natural selection in speciation remains poorly understood. In particular, it remains unclear how selection at a few genes can lead to genomewide divergence and the formation of distinct species. We used a particularly attractive clear-cut case of recent plant ecological speciation to investigate the demography and genomic bases of species formation driven by adaptation to contrasting conditions. High-altitude Senecio aethnensis and low-altitude S. chrysanthemifolius live at the extremes of a mountain slope on Mt. Etna, Sicily, and form a hybrid zone at intermediate altitudes but remain morphologically distinct. Genetic differentiation of these species was analyzed at the DNA polymorphism and gene expression levels by high-throughput sequencing of transcriptomes from multiple individuals. Out of ∼18,000 genes analyzed, only a small number (90) displayed differential expression between the two species. These genes showed significantly elevated species differentiation (FST and Dxy), consistent with diversifying selection acting on these genes. Genomewide genetic differentiation of the species is surprisingly low (FST = 0.19), while ∼200 genes showed significantly higher (false discovery rate < 1%; mean outlier FST > 0.6) interspecific differentiation and evidence for local adaptation. Diversifying selection at only a handful of loci may be enough for the formation and maintenance of taxonomically well-defined species, despite ongoing gene flow. This provides an explanation of why many closely related species (in plants, in particular) remain phenotypically and ecologically distinct despite ongoing hybridization, a question that has long puzzled naturalists and geneticists alike.
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DOI：
10.1093/bioinformatics/btp572
发表时间：
2009-12-01
期刊：
Bioinformatics (Oxford, England)
影响因子：
--
作者：
Filatov DA
通讯作者：
Filatov DA
影响因子：
3.5
作者：
Aiuppa, A;Bellomo, S;Longo, M
通讯作者：
Longo, M
影响因子：
3.3
作者：
Comes, HP;Abbott, RJ
通讯作者：
Abbott, RJ
影响因子：
9.2
作者：
Chibalina, Margarita V.;Filatov, Dmitry A.
通讯作者：
Filatov, Dmitry A.
影响因子：
3
作者：
Chapman, MA;Forbes, DG;Abbott, RJ
通讯作者：
Abbott, RJ