Data from: Interspecific genetics of speciation phenotypes: song and preference coevolution in Hawaiian crickets

Understanding the genetic architecture of traits involved in premating isolation between recently diverged lineages can provide valuable insight regarding the mode and tempo of speciation. The repeated coevolution of male courtship song and female preference across the species radiation of Laupala crickets presents an unusual opportunity to compare the genetic basis of divergence across independent evolutionary histories. Previous studies of one pair of species revealed a polygenic basis (including a significant X chromosome contribution) to quantitative differences in male song and female acoustic preference. Here we studied interspecific crosses between two phenotypically less diverged species that represents a phylogenetically independent occurrence of intersexual signaling evolution. We found patterns consistent with an additive polygenic basis to differentiation in both song and preference (nE=5.3 and 5.1 genetic factors, respectively), and estimate a moderate contribution of the X chromosome (7.6%) of similar magnitude to that observed for Laupala species with nearly twice the phenotypic divergence. Together, these findings suggest a similar genetic architecture underlying the parallel evolution of sexual characters in this genus and provide a counterexample to prevailing theory predicting an association between early lineage divergence and sex-linked ‘major genes’.

解析新近分化支系间交配前隔离相关性状的遗传架构，可为阐明物种形成的模式与速率提供极具价值的洞见。在Laupala蟋蟀属（Laupala）的物种辐射演化过程中，雄性求偶鸣曲与雌性偏好的反复协同演化，为对比独立演化历史下分化的遗传基础提供了难得的契机。此前针对一对物种的研究表明，雄性鸣曲与雌性声学偏好的数量性状差异以多基因遗传架构为基础，其中X染色体贡献显著。本研究针对两个表型分化程度较低的物种开展种间杂交实验，二者代表了一次独立的性信号演化系统发育事件。我们发现鸣曲与偏好的分化均符合加性多基因遗传架构（分别对应5.3和5.1个遗传因子，即nE=5.3与5.1），且估算得到X染色体的中等贡献占比为7.6%，其效应规模与表型分化程度近乎为其两倍的Laupala蟋蟀属物种中观测到的结果相近。综上，本研究结果表明该属内性性状的平行演化具有相似的遗传架构，同时也为当前主流理论——该理论预测早期支系分化与性连锁‘主效基因’存在关联——提供了反例。