Data from: The genetics of mate preferences in hybrids between two young and sympatric Lake Victoria cichlid species

The genetic architecture of mate preferences is likely to affect significant evolutionary processes, including speciation and hybridization. Here, we investigate laboratory hybrids between a pair of sympatric Lake Victoria cichlid fish species that appear to have recently evolved from a hybrid population between similar predecessor species. The species demonstrate strong assortative mating in the laboratory, associated with divergent male breeding coloration (red dorsum versus blue). We show in a common garden experiment, using DNA-based paternity testing, that the strong female mate preferences among males of the two species are fully recovered in a large fraction of their F2 hybrid generation. Individual hybrid females often demonstrated consistent preferences in multiple mate choice trials (more than or equal to five) across a year or more. This result suggests that female mate preference is influenced by relatively few major genes or genomic regions. These preferences were not changed by experience of a successful spawning event with a male of the non-preferred species in a no-choice single-male trial. We found no evidence for imprinting in the F2 hybrids, although the F1 hybrid females may have been imprinted on their mothers. We discuss this nearly Mendelian inheritance of consistent innate mate preferences in the context of speciation theory.

择偶偏好的遗传架构（genetic architecture）极可能对物种形成（speciation）、杂交（hybridization）等关键演化进程产生显著影响。本研究针对一对同域分布的维多利亚湖慈鲷（Lake Victoria cichlid）开展实验室杂交实验，这两个物种据推测由近缘祖先物种的杂交种群新近演化而来。该对物种在实验室环境中表现出强烈的选型交配（assortative mating）现象，这与其雄性繁殖体色的分化紧密相关——雄性分别具有红色背部与蓝色体色。本研究通过同质园实验（common garden experiment）结合基于DNA的亲子鉴定（paternity testing）证实：两个物种雄性间存在的强烈雌性择偶偏好，在其大部分F₂杂交后代群体中得到了完整重现。单个杂交雌性个体在为期一年及以上的多次择偶试验（不少于5次）中，往往表现出稳定一致的偏好。该结果表明，雌性择偶偏好受数量相对较少的主效基因（major genes）或基因组区域（genomic regions）调控。在无选择单雄试验（no-choice single-male trial）中，杂交雌性与非偏好性雄性成功产卵的经历，并未改变其原本的择偶偏好。尽管F₁杂交雌性个体可能受母本印记（imprinting）影响，但本研究未在F₂杂交后代中发现印记效应的相关证据。本研究结合物种形成理论（speciation theory），对这种近乎孟德尔式遗传的稳定先天择偶偏好展开了讨论。