Department of Biology, Duke University, Durham, North Carolina 27708.
University Program in Genetics and Genomics, Duke University, Durham, North Carolina 27708.
Genetics. 2018 Sep;210(1):263-274. doi: 10.1534/genetics.118.301250. Epub 2018 Jul 26.
Phenotypic plasticity is facilitated by epigenetic regulation, and remnants of such regulation may persist after plasticity-inducing cues are gone. However, the relationship between plasticity and transgenerational epigenetic memory is not understood. Dauer diapause in provides an opportunity to determine how a plastic response to the early-life environment affects traits later in life and in subsequent generations. We report that, after extended diapause, postdauer worms initially exhibit reduced reproductive success and greater interindividual variation. In contrast, F3 progeny of postdauers display increased starvation resistance and lifespan, revealing potentially adaptive transgenerational effects. Transgenerational effects are dependent on the duration of diapause, indicating an effect of extended starvation. In agreement, RNA-seq demonstrates a transgenerational effect on nutrient-responsive genes. Further, postdauer F3 progeny exhibit reduced gene expression plasticity, suggesting a trade-off between plasticity and epigenetic memory. This work reveals complex effects of nutrient stress over different time scales in an animal that evolved to thrive in feast and famine.
表型可塑性是由表观遗传调控促成的,而且在诱导可塑性的线索消失后,这种调控的残余可能仍然存在。然而,可塑性和跨代表观遗传记忆之间的关系尚不清楚。 提供了一个机会,可以确定对早期环境的可塑性反应如何影响生命后期和后代的特征。我们报告说,在长时间的休眠之后,后休眠期的线虫最初表现出繁殖成功率降低和个体间变异性增加。相比之下,后休眠期的 F3 后代表现出对饥饿的抵抗力和寿命增加,显示出潜在的适应性跨代效应。跨代效应取决于休眠的持续时间,表明延长饥饿的影响。这与 RNA-seq 对营养反应基因的跨代效应一致。此外,后休眠期 F3 后代表现出较低的基因表达可塑性,这表明可塑性和表观遗传记忆之间存在权衡。这项工作揭示了在一种进化为在丰饶和饥荒中茁壮成长的动物中,不同时间尺度上营养胁迫的复杂影响。