McCormick Gail L, Robbins Travis R, Cavigelli Sonia A, Langkilde Tracy
Department of Biology, Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park, PA 16802, USA; The Center for Brain, Behavior and Cognition, The Huck Institute of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA.
Department of Biology, Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park, PA 16802, USA.
Horm Behav. 2017 Jan;87:115-121. doi: 10.1016/j.yhbeh.2016.11.010. Epub 2016 Nov 15.
Exposure to stressors can affect an organism's physiology and behavior as well as that of its descendants (e.g. through maternal effects, epigenetics, and/or selection). We examined the relative influence of early life vs. transgenerational stress exposure on adult stress physiology in a species that has populations with and without ancestral exposure to an invasive predator. We raised offspring of eastern fence lizards (Sceloporus undulatus) from sites historically invaded (high stress) or uninvaded (low stress) by predatory fire ants (Solenopsis invicta) and determined how this different transgenerational exposure to stress interacted with the effects of early life stress exposure to influence the physiological stress response in adulthood. Offspring from these high- and low-stress populations were exposed weekly to either sub-lethal attack by fire ants (an ecologically relevant stressor), topical treatment with a physiologically-appropriate dose of the stress-relevant hormone, corticosterone (CORT), or a control treatment from 2 to 43weeks of age. Several months after treatments ended, we quantified plasma CORT concentrations at baseline and following restraint, exposure to fire ants, and adrenocorticotropic hormone (ACTH) injection. Exposure to fire ants or CORT during early life did not affect lizard stress physiology in adulthood. However, offspring of lizards from populations that had experienced multiple generations of fire ant-invasion exhibited more robust adult CORT responses to restraint and ACTH-injection compared to offspring from uninvaded populations. Together, these results indicate that transgenerational stress history may be at least as important, if not more important, than early life stress in affecting adult physiological stress responses.
暴露于应激源会影响生物体及其后代的生理和行为（例如通过母体效应、表观遗传学和/或选择）。我们研究了在一个存在有或没有祖先暴露于入侵性捕食者的种群的物种中，早期生活应激与跨代应激暴露对成年应激生理学的相对影响。我们饲养了来自历史上被掠食性火蚁（红火蚁）入侵（高应激）或未被入侵（低应激）地点的东部围栏蜥蜴（强棱蜥）的后代，并确定这种不同的跨代应激暴露如何与早期生活应激暴露的影响相互作用，以影响成年期的生理应激反应。这些高应激和低应激种群的后代在2至43周龄时每周接受一次处理，处理方式包括被火蚁进行亚致死攻击（一种与生态相关的应激源）、用生理适当剂量的与应激相关的激素皮质酮（CORT）进行局部处理或对照处理。处理结束几个月后，我们在基线以及在受到束缚、暴露于火蚁和注射促肾上腺皮质激素（ACTH）后，对血浆CORT浓度进行了量化。早期生活中暴露于火蚁或CORT对成年蜥蜴的应激生理学没有影响。然而，与未被入侵种群的后代相比，经历了多代火蚁入侵的种群的蜥蜴后代在成年期对束缚和ACTH注射表现出更强的CORT反应。总之，这些结果表明，在影响成年生理应激反应方面，跨代应激史可能至少与早期生活应激同样重要，甚至更为重要。
