Data from: Paternal-effects in a terrestrial ectotherm are temperature dependent but no evidence for adaptive effects

1. Global rising of average temperatures and increase in extreme climatic events may largely impact animal survival and reproduction. Yet, how variation in temperature may affect male fertility, in particular ejaculate traits, and whether this can in turn affect offspring fitness, is seldom addressed. Paternal effects may be of key importance as they could impact the rate and direction of evolutionary change in response to climate change. 2. We tested the effects of temperature experienced by males on sperm traits, and asked whether the paternal environmental temperature affected offspring phenotype. We further explored the potential for paternal effects to be adaptive, which would occur when offspring fitness increased under the same environmental conditions experienced by the fathers. We exposed male field crickets to high or low temperatures at two life stages, either throughout development or as adults, and tested sperm traits (number and quality) and offspring fitness (hatching success and survival). We further assessed sperm traits in offspring, after they had also been exposed to the same or different temperature experienced by their father. 3. We found that temperature affected sperm traits depending on the life-stage of individuals. When the exposure was given during adulthood, males exposed to high temperature produced less sperm and of lower quality compared to males exposed to the lower temperature, while if exposure was given during development males exposed to high temperature produced more sperm and of better quality compared to males exposed to low temperatures. Offspring fitness was significantly affected by paternal temperature, evidence for anticipatory paternal effects on sperm traits was not found. 4. Our study indicates that temperature can mediate cross-generational effects, and that paternal effects may be mediated by changes in temperature and therefore much more widespread in nature than previously assumed.

1. 全球平均气温上升与极端气候事件频发，或对动物的生存与繁殖造成显著影响。然而，气温波动如何影响雄性生育能力——尤其是射精性状（ejaculate traits）——以及这是否会进一步影响后代适合度（offspring fitness），此类问题迄今鲜有研究涉足。父本效应（paternal effects）可能至关重要，因其可影响物种响应气候变化的演化速率与方向。
2. 本研究探究了雄性经历的气温对精子性状的影响，并验证了父本所处环境温度是否会对子代表型产生作用。我们进一步探索了父本效应的适应性潜力：当后代在与父本相同的环境条件下适合度提升时，即体现出适应性父本效应。我们将雄性田野蟋蟀（field crickets）在两个生命阶段分别暴露于高温或低温环境中——全程发育阶段，或仅成年阶段——并检测了其精子性状（数量与质量）以及后代适合度（孵化成功率与存活率）。此外，在后代同样经历与父本相同或不同的温度环境后，我们还评估了后代的精子性状。
3. 研究结果显示，气温对精子性状的影响取决于个体所处的生命阶段。当暴露处理发生在成年阶段时，相较于低温暴露的雄性，高温暴露的雄性所产生的精子数量更少、质量更差；而当暴露处理发生在发育阶段时，高温暴露的雄性所产生的精子数量更多、质量更佳。父本所处温度会显著影响后代适合度，但未发现针对精子性状的预期性父本效应的相关证据。
4. 本研究表明，气温可介导跨代效应（cross-generational effects），且父本效应或通过气温变化实现介导，因此其在自然界中的分布范围或远超此前的学术认知。