Genetic architecture of a body colour cline in Drosophila americana.
Genetic architecture of a body colour cline in Drosophila americana.
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美洲果蝇体色系的遗传结构。
DOI：
10.1111/mec.15531
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发表时间：
2020
影响因子：
4.9
通讯作者：
Wittkopp,PatriciaJ
中科院分区：
文献类型：
--
作者：
Sramkoski,LisaL;McLaughlin,WesleyN;Cooley,ArielleM;Yuan,DavidC;John,Alisha;Wittkopp,PatriciaJ
一个物种内的表型变异往往在地理上以渐变群的形式构成。在美洲果蝇（Drosophila americana）中，北美洲存在着一个身体颜色的纵向渐变群，这似乎是由于当地的适应。tanandebonygenes被假设为促成了这一渐变群，在美洲龙中发现了这两个基因的等位基因，使体色变浅。这些等位基因在序列和功能上与美洲果蝇的姐妹种--新美洲果蝇中固定的等位基因相似。在这里，我们研究了这些D. novamexicana-样等位基因在D. americana中的频率和地理分布。在从21个地理位置分离的100多个美洲果蝇菌株的等位基因中，我们未能鉴定出与先前描述的新墨西哥果蝇样等位基因具有与新墨西哥果蝇一样多的序列相似性的其他等位基因。然而，通过对来自20个地理位置的51个美洲锥虫株进行遗传分析，我们发现了一个新的bone等位基因和一个新的在美洲锥虫中分离的等位基因，它们在功能上与美洲锥虫的novamexicana等位基因等同。另外5个等位基因也显示出功能相似性的边缘证据。然而，鉴于这些等位基因的稀有性，我们得出结论，它们不太可能驱动色素沉着渐变群。事实上，分析的51个回交群体的表型分布表明一个更复杂的遗传结构，在数量和影响的基因座改变色素的多样性观察内和种群之间ofD. americana。这种遗传异质性对相关研究和基因组扫描的倾斜变化提出了挑战，但在自然群体中可能很常见。
Phenotypic variation within a species is often structured geographically in clines. InDrosophila americana, a longitudinal cline for body colour exists within North America that appears to be due to local adaptation. Thetanandebonygenes have been hypothesized to contribute to this cline, with alleles of both genes that lighten body colour found inD. americana. These alleles are similar in sequence and function to the allele fixed inD. americana'smore lightly pigmented sister species,Drosophila novamexicana. Here, we examine the frequency and geographic distribution of theseD. novamexicana‐like alleles inD. americana. Among alleles from over 100 strains ofD. americanaisolated from 21 geographic locations, we failed to identify additional alleles oftanorebonywith as much sequence similarity toD. novamexicanaas theD. novamexicana‐like alleles previously described. However, using genetic analysis of 51D. americanastrains derived from 20 geographic locations, we identified one new allele ofebonyand one new allele oftansegregating inD. americanathat are functionally equivalent to theD. novamexicanaallele. An additional 5 alleles oftanalso showed marginal evidence of functional similarity. Given the rarity of these alleles, however, we conclude that they are unlikely to be driving the pigmentation cline. Indeed, phenotypic distributions of the 51 backcross populations analysed indicate a more complex genetic architecture, with diversity in the number and effects of loci altering pigmentation observed both within and among populations ofD. americana. This genetic heterogeneity poses a challenge to association studies and genomic scans for clinal variation, but might be common in natural populations.