Data from: Mating system transitions drive life span 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 life span in Pristionchus nematodes, where self-fertile hermaphrodites have replaced females multiple times independently throughout the genus (androdioecy). By measuring adult life span for 11 species (6 dioecious, 5 androdioecious), we found that life span 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 life span in self-fertilizing hermaphrodites or in mated females. Furthermore, we found that sexual dimorphism in life span varied among dioecious species, with females generally outliving males. Finally, we documented intraspecific variation for life span and cuticular disease (blistering) prevalence in Pristionchus pacificus, a model system for evolutionary-developmental biology. This work demonstrates that mating system transitions and life span evolution are linked in Pristionchus nematodes and provides a foundation for future comparative and mechanistic studies of aging in this genus.

两性间的相互作用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的演化重要性的有力工具。我们以隐杆线虫属（Pristionchus）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育的雌雄同体，取代了雌性个体，该生殖策略被称为雄两性同体型（androdioecy）。我们对11个隐杆线虫物种（6个为雌雄异体型、5个为雄两性同体型）的成虫寿命进行测定后发现，相较于近缘类群的雌性，雌雄同体的寿命显著更短。该效应并非繁殖成本所致：自育雌雄同体或交配雌性的产卵量并未与寿命形成可靠的繁殖代价权衡。此外，我们发现不同雌雄异体物种间的寿命性二态性存在差异，雌性通常比雄性更长寿。最后，我们在进化发育生物学的模式生物太平洋隐杆线虫（Pristionchus pacificus）中，记录了其寿命与表皮起泡病患病率的种内变异。本研究表明，隐杆线虫属的交配系统转变与寿命演化存在关联，可为该属衰老相关的比较研究与机制研究奠定基础。