Phylogeographic patterns in Drosophila montana
Phylogeographic patterns in Drosophila montana
复制标题
DOI：
10.1111/j.1365-294x.2006.03215.x
复制
发表时间：
2007-03-01
影响因子：
4.9
通讯作者：
Butlin, R. K.
中科院分区：
文献类型：
--
作者：
Mirol, P. M.;Schaefer, M. A.;Butlin, R. K.
果蝇种组提供了宝贵的机会，研究染色体重排和交配信号在物种形成中的作用。这13个物种被分为两个亚群，蒙大拿和维里利斯“门”。在核型和声音信号方面，蒙大拿门内的物种之间的差异要比雄性门内的物种之间的差异大。蒙大拿果蝇（Drosophila montana）是蒙大拿果蝇门中的一个分歧种。本文分析了D.蒙大拿州，以提供一个框架，了解人口之间的声音信号的分歧。我们分析了108个D.蒙大拿州覆盖了大部分物种的分布范围。该物种在北美和斯堪的纳维亚种群之间表现出明显的遗传分化。微卫星等位基因频率和线粒体DNA单倍型在加拿大、美国和芬兰群体间具有显著的F（ST）值。基于微卫星频率的群体结构的贝叶斯分析显示了四个遗传上不同的群体，对应于这三个群体加上来自日本的一个小样本。一个基于线粒体单倍型的网络显示了两个形状和变异性非常不同的芬兰分支，另一个分支具有来自北美和日本的所有序列。全是D。蒙大拿州人口显示出人口扩张的证据，但结合分析推断的模式在人口之间存在差异。斯堪的纳维亚和北美的分支之间的分歧时间估计范围从450 000至900 000年，在加拿大和美国的人口可能代表不同的避难种群的后代。长期分离D.蒙大拿种群可能提供了雄性信号性状分化的机会，特别是歌声的载波频率，但在种群扩张期间放松性选择可能是必要的。
The Drosophila virilis species group offers valuable opportunities for studying the roles of chromosomal re-arrangements and mating signals in speciation. The 13 species are divided into two subgroups, the montana and virilis 'phylads'. There is greater differentiation among species within the montana phylad in both karyotype and acoustic signals than exists among members of the virilis phylad. Drosophila montana is a divergent species which is included in the montana phylad. Here, we analyse the phylogeography of D. montana to provide a framework for understanding divergence of acoustic signals among populations. We analysed mitochondrial sequences corresponding to the cytochrome oxidase I and cytochrome oxidase II genes, as well as 16 microsatellite loci, from 108 lines of D. montana covering most of the species' range. The species shows a clear genetic differentiation between North American and Scandinavian populations. Microsatellite allele frequencies and mitochondrial DNA haplotypes gave significant F(ST) values between populations from Canada, USA and Finland. A Bayesian analysis of population structure based on the microsatellite frequencies showed four genetically distinct groups, corresponding to these three populations plus a small sample from Japan. A network based on mitochondrial haplotypes showed two Finnish clades of very different shape and variability, and another clade with all sequences from North America and Japan. All D. montana populations showed evidence of demographic expansion but the patterns inferred by coalescent analysis differed between populations. The divergence times between Scandinavian and North American clades were estimated to range from 450 000 to 900 000 years with populations in Canada and the USA possibly representing descendants of different refugial populations. Long-term separation of D. montana populations could have provided the opportunity for differentiation observed in male signal traits, especially carrier frequency of the song, but relaxation of sexual selection during population expansion may have been necessary.