Genomic hotspots for adaptation: the population genetics of Müllerian mimicry in Heliconius erato.
Genomic hotspots for adaptation: the population genetics of Müllerian mimicry in Heliconius erato.
复制标题
DOI：
10.1371/journal.pgen.1000796
复制
发表时间：
2010-02-05
期刊：
影响因子：
4.5
通讯作者：
McMillan WO
中科院分区：
文献类型：
--
作者：
Counterman BA;Araujo-Perez F;Hines HM;Baxter SW;Morrison CM;Lindstrom DP;Papa R;Ferguson L;Joron M;Ffrench-Constant RH;Smith CP;Nielsen DM;Chen R;Jiggins CD;Reed RD;Halder G;Mallet J;McMillan WO
Heliconius蝴蝶的翅型进化提供了一些自然选择适应的最引人注目的例子。控制模式变异的基因是孟德尔基因座大效应的经典例子，其中等位基因变异导致大的和离散的表型变化，并负责跨属的收敛和高度发散的翼型进化。我们的特点是核苷酸变异，基因型的表型协会，连锁不平衡（LD），和候选基因的表达模式，在两个未连接的基因组间隔控制黄色和红翼模式之间的变化模仿形式的Heliconius erato。尽管非常强大的自然选择的颜色模式，我们既没有看到一个强大的减少遗传多样性，也没有证据表明延长LD在任何图案间隔。这一观察结果突出了重组可以消除自然种群中选择特征的程度，并且与适应性辐射或控制它的等位基因相当古老的假设一致。然而，在这两个图案间隔，我们确定了SNPs聚集在几个编码区，与颜色模式表型密切相关。有趣的是，编码区与相关的SNPs被广泛分离，这表明颜色模式等位基因可能由多个功能位点组成，符合先前将这些基因座描述为“超基因”。检测这些区域侧翼基因的基因表达水平。erato及其共模拟物H. Melpomene的研究表明，与驱动蛋白具有高度序列相似性的基因在调节模式中起关键作用，并为跨共模拟谱系的基因调控的平行变化提供了令人信服的证据。这些颜色模式基因座的复杂遗传结构与适应性遗传研究中经常发现的单一偶然突变形成鲜明对比，但可能更能说明自然种群中大部分适应性变异的遗传变化类型。确定导致有益变异的遗传变化对于理解生物体如何适应至关重要。在这里，我们使用映射，人口遗传分析和基因表达研究相结合，以确定负责表型进化的新热带蝴蝶Heliconius erato的基因组区域。H. erato及其共模拟物H.在中美洲和南美洲，它们那警告性的彩色翅膀图案经历了平行和和谐的辐射。H.花型辐射是孟德尔大效应基因座的典型例子，受到强烈的自然选择。尽管如此，我们没有看到一个明确的分子信号，最近的自然选择，这表明H。埃拉托色型辐射，或其下的等位基因，可能是相当古老的。此外，而不是单一的基因座，遗传模式表明，多个，广泛分散的基因座可能是H。埃拉托。其中一个基因座，驱动蛋白基因，在两个黑腹果蝇的翅型形成过程中表现出了种族间的平行表达差异。erato和H. melpomene，这表明它在图案变化中起着重要作用。在自然发生的H.埃拉托杂交区意味着更精细的遗传解剖将使我们能够定位致病位点，并更好地了解这种非凡的适应性辐射的历史和分子基础。
Wing pattern evolution in Heliconius butterflies provides some of the most striking examples of adaptation by natural selection. The genes controlling pattern variation are classic examples of Mendelian loci of large effect, where allelic variation causes large and discrete phenotypic changes and is responsible for both convergent and highly divergent wing pattern evolution across the genus. We characterize nucleotide variation, genotype-by-phenotype associations, linkage disequilibrium (LD), and candidate gene expression patterns across two unlinked genomic intervals that control yellow and red wing pattern variation among mimetic forms of Heliconius erato. Despite very strong natural selection on color pattern, we see neither a strong reduction in genetic diversity nor evidence for extended LD across either patterning interval. This observation highlights the extent that recombination can erase the signature of selection in natural populations and is consistent with the hypothesis that either the adaptive radiation or the alleles controlling it are quite old. However, across both patterning intervals we identified SNPs clustered in several coding regions that were strongly associated with color pattern phenotype. Interestingly, coding regions with associated SNPs were widely separated, suggesting that color pattern alleles may be composed of multiple functional sites, conforming to previous descriptions of these loci as “supergenes.” Examination of gene expression levels of genes flanking these regions in both H. erato and its co-mimic, H. melpomene, implicate a gene with high sequence similarity to a kinesin as playing a key role in modulating pattern and provides convincing evidence for parallel changes in gene regulation across co-mimetic lineages. The complex genetic architecture at these color pattern loci stands in marked contrast to the single casual mutations often identified in genetic studies of adaptation, but may be more indicative of the type of genetic changes responsible for much of the adaptive variation found in natural populations. Identifying the genetic changes responsible for beneficial variation is essential for understanding how organisms adapt. Here, we use a combination of mapping, population genetic analysis, and gene expression studies to identify the genomic regions responsible for phenotypic evolution in the Neotropical butterfly Heliconius erato. H. erato, together with its co-mimic H. melpomene, have undergone parallel and concordant radiations in their warningly colored wing patterns across Central and South America. The “genes” underlying the H. erato color pattern radiation are classic examples of Mendelian loci of large effect and are under strong natural selection. Nonetheless, we do not see a clear molecular signal of recent natural selection, suggesting that the H. erato color pattern radiation, or the alleles that underlie it, may be quite old. Moreover, rather than being single locus, the genetic patterns suggest that multiple, widely dispersed loci may underlie pattern variation in H. erato. One of these loci, a kinesin gene, shows parallel expression differences between races during wing pattern formation in both H. erato and H. melpomene, suggesting that it plays an important role in pattern variation. High rates of recombination within naturally occurring H. erato hybrid zones mean that finer genetic dissection will allow us to localize causative sites and better understand the history and molecular basis of this extraordinary adaptive radiation.
登录
查看更多内容
影响因子：
4.5
作者：
Baxter SW;Nadeau NJ;Maroja LS;Wilkinson P;Counterman BA;Dawson A;Beltran M;Perez-Espona S;Chamberlain N;Ferguson L;Clark R;Davidson C;Glithero R;Mallet J;McMillan WO;Kronforst M;Joron M;Ffrench-Constant RH;Jiggins CD
通讯作者：
Jiggins CD
影响因子：
4.9
作者：
Cano, J. M.;Matsuba, C.;Merila, J.
通讯作者：
Merila, J.
DOI：
10.1111/j.1600-0749.2005.00277.x
发表时间：
2006-02-01
期刊：
PIGMENT CELL RESEARCH
影响因子：
--
作者：
Boyle, RT;McNamara, JC
通讯作者：
McNamara, JC
DOI：
10.1111/j.1095-8312.2007.00830.x
发表时间：
2007-10-01
影响因子：
1.9
作者：
Beltran, Margarita;Jiggins, Chris D.;Mallet, James
通讯作者：
Mallet, James
DOI：
10.1073/pnas.91.14.6491
发表时间：
1994-07-05
影响因子：
11.1
作者：
BROWER, AVZ
通讯作者：
BROWER, AVZ