Data from: The extent and genetic basis of phenotypic divergence in life history traits in Mimulus guttatus

Differential natural selection acting on populations in contrasting environments often results in adaptive divergence in multivariate phenotypes. Multivariate trait divergence across populations could be caused by selection on pleiotropic alleles or through many independent loci with trait-specific effects. Here, we assess patterns of association between a suite of traits contributing to life history divergence in the common monkeyflower, Mimulus guttatus, and examine the genetic architecture underlying these correlations. A common garden survey of 74 populations representing annual and perennial strategies from across the native range revealed strong correlations between vegetative and reproductive traits. To determine whether these multitrait patterns arise from pleiotropic or independent loci, we mapped QTLs using an approach combining high-throughput sequencing with bulk segregant analysis on a cross between populations with divergent life histories. We find extensive pleiotropy for QTLs related to flowering time and stolon production, a key feature of the perennial strategy. Candidate genes related to axillary meristem development co-localize with the QTLs in a manner consistent with either pleiotropic or independent QTL effects. Further, these results are analogous to previous work showing pleiotropy-mediated genetic correlations within a single population of M. guttatus experiencing heterogeneous selection. Our findings of strong multivariate trait associations and pleiotropic QTLs suggest that patterns of genetic variation may determine the trajectory of adaptive divergence.差异自然选择（Differential natural selection）作用于异质环境中的种群时，往往会导致多变量表型（multivariate phenotypes）产生适应性分化。种群间的多性状分化可能由多效等位基因（pleiotropic alleles）驱动，也可能源于多个具备性状特异性效应的独立基因座（independent loci）。本研究以普通猴面花（Mimulus guttatus，common monkeyflower）为对象，解析与其生活史分化相关的一系列性状的关联模式，并探究这些关联背后的遗传结构（genetic architecture）。我们对覆盖其原生分布区的74个种群开展了共同花园实验调查，这些种群涵盖了一年生和多年生两种生活型策略，结果发现营养性状（vegetative traits）与生殖性状（reproductive traits）之间存在显著相关性。为明确这类多性状模式究竟源于多效基因座还是独立基因座，我们采用结合高通量测序（high-throughput sequencing）与集团分离分析（bulk segregant analysis）的方法，对具有不同生活史的种群间的杂交组合开展了数量性状基因座（Quantitative Trait Loci，QTL）定位。研究发现，与开花时间（flowering time）及多年生生活型的关键特征——匍匐茎产生（stolon production）相关的数量性状基因座存在广泛的多效性。与腋芽分生组织发育（axillary meristem development）相关的候选基因与这些数量性状基因座共定位，该模式与多效或独立数量性状基因座的效应均相符。此外，本研究结果与此前一项在经历异质选择（heterogeneous selection）的普通猴面花单一种群中发现的、由多效性介导的遗传相关性的研究结果一致。我们关于强烈多性状关联及多效性数量性状基因座的研究结果表明，遗传变异格局或可决定适应性分化的演化轨迹。