Stickleback F2 generation transgenerational plasticity experiment: egg and body size data

Nongenetic inheritance mechanisms such as transgenerational plasticity (TGP) can buffer populations against rapid environmental change such as ocean warming. Yet, little is known about how long these effects persist and whether they are cumulative over generations. Here, we tested for adaptive TGP in response to simulated ocean warming across parental and grandparental generations of marine sticklebacks. Grandparents were acclimated for two months during reproductive conditioning, whereas parents experienced developmental acclimation, allowing us to compare the fitness consequences of short-term vs. prolonged exposure to elevated temperature across multiple generations. We found that reproductive output of F1 adults was primarily determined by maternal developmental temperature, but carry-over effects from grandparental acclimation environments resulted in cumulative negative effects of elevated temperature on hatching success. In very early stages of growth, F2 offspring reached larger sizes in their respective paternal and grandparental environment down the paternal line, suggesting that other factors than just the paternal genome may be transferred between generations. In later growth stages, maternal and maternal granddam environments strongly influenced offspring body size, but in opposing directions, indicating that the mechanism(s) underlying the transfer of environmental information may have differed between acute and developmental acclimation experienced by the two generations. Taken together, our results suggest that the fitness consequences of parental and grandparental TGP are highly context dependent, but will play an important role in mediating some of the impacts of rapid climate change in this system.

跨代可塑性（transgenerational plasticity, TGP）这类非遗传继承机制，能够帮助种群抵御海洋变暖等快速环境变化。然而，目前对这类效应的持续时长以及是否会随世代累积仍知之甚少。本研究针对海洋棘鱼的亲代和祖代世代，开展了模拟海洋变暖下的适应性跨代可塑性实验。祖代在生殖驯化期间接受了为期两个月的温度驯化，而亲代则经历了发育阶段的温度驯化，这使得我们能够对比多世代中短期与长期暴露于高温环境带来的适合度后果。研究发现，F1成体的繁殖产出主要受母体发育阶段温度的影响，但祖代驯化环境带来的遗留效应，会使高温对孵化成功率产生累积的负面影响。在生长的极早期阶段，F2后代在父系对应的祖代与亲代高温环境中体型更大，这表明世代间传递的可能并非仅父本基因组，还存在其他因素。而在生长后期，母本及外祖母的环境会显著影响后代体型，但二者的影响方向相反，这表明环境信息传递的潜在机制，可能在两代个体所经历的急性驯化与发育驯化之间存在差异。综合来看，本研究结果表明，亲代与祖代跨代可塑性带来的适合度后果具有极强的情境依赖性，但该效应在本研究体系中，将在缓解快速气候变化带来的部分影响方面发挥重要作用。