Data from: Mating system transitions drive lifespan evolution in Pristionchus nematodes

Interactions between the sexes influence evolution at many scales, but not all animal species conform to the familiar male-female (dioecious) mating system; such taxa are powerful tools for studying the evolutionary importance of sexual selection and conflict on all manner of life history traits, including longevity. We tested for an effect of mating system on adult lifespan in Prisitonchus nematodes, where self-fertile hermaphrodites have replaced females multiple times independently throughout the genus (androdioecy). By measuring adult lifespan for eleven species (six dioecious, five androdioecious), we found that lifespan is considerably shorter in hermaphrodites relative to closely related females. This effect is not a cost of reproduction; brood size did not reliably trade-off with lifespan in self-fertilizing hermaphrodites, nor in mated females. Furthermore, we found that sexual dimorphism in lifespan varied among dioecious species, with females generally outliving males. Finally, we documented intraspecific variation for lifespan and cuticular disease (blistering) prevalence in P. pacificus, a model system for evolutionary-developmental biology. This work demonstrates that mating system transitions and lifespan evolution are linked in Prisitonchus nematodes, and provides a foundation for future comparative and mechanistic studies of aging in this genus.

两性间的相互作用可在多个尺度上影响生物演化，但并非所有动物物种都遵循广为人知的雌雄异体（dioecious）交配系统；此类类群是研究性选择与性冲突对包括寿命在内的各类生活史特征演化重要性的有力工具。我们以薄口线虫属（Pristionchus）线虫为研究对象，测试了交配系统对其成虫寿命的影响，该属内多次独立演化出可自我繁殖的雌雄同体以取代雌性个体，形成雄全同体（androdioecy）交配系统。通过对11个物种（6个雌雄异体物种、5个雄全同体物种）的成虫寿命进行测定，我们发现相较于其近缘雌性个体，雌雄同体的寿命显著更短。该效应并非繁殖成本所致：无论是进行自我繁殖的雌雄同体，还是已交配的雌性个体，其产卵量均未与寿命呈现稳定的权衡关系。此外，我们发现不同雌雄异体物种间的寿命两性异形存在差异，雌性通常比雄性更长寿。最后，我们针对进化发育生物学模式生物——太平洋薄口线虫（P. pacificus），记录了其种内寿命变异与表皮疾病（起泡）的流行情况。本研究证实，薄口线虫属的交配系统转变与寿命演化存在关联，为该属衰老相关的比较研究与机制研究奠定了基础。