Data from: Inbreeding interferes with the heat-shock response

Inbreeding is typically detrimental to individual fitness, with negative effects being often exaggerated in stressful environments. However, the causal mechanisms underlying inbreeding depression in general and the often increased susceptibility to stress in particular are not well understood. We here test whether inbreeding interferes with the heat-shock response, comprising an important component of the stress response which may therefore underscore sensitivity to stress. To this end we subjected the tropical butterfly Bicyclus anynana to a full-factorial design with three temperatures and three levels of inbreeding, and measured the expression of heat-shock protein (HSP) 70 via qPCR. HSP70 expression increased after exposure to heat as compared with cold or control conditions. Most strikingly, inbreeding strongly interfered with the heat-shock response, with inbred individuals showing a very weak upregulation of HSP70 only. Our results thus indicate that, in our study organism, interference with the heat-shock response may be one mechanism underlying reduced fitness of inbred individuals, especially when exposed to stressful conditions. However, these indications need to be corroborated using a broader range of different temperatures, genes and taxa.

近交通常对个体适合度产生不利影响，且其负面影响在胁迫环境中往往更为突出。然而，学界目前对近交衰退的整体因果机制，尤其是近交个体为何更易受到胁迫影响的具体原因，尚未形成充分认知。本研究旨在探究近交是否会干扰热激响应——热激响应作为胁迫响应的关键组成部分，其异常或可解释近交个体的胁迫敏感性。为此，我们以热带蝴蝶Bicyclus anynana为实验对象，采用三温度×三近交水平的全因子实验设计，并通过qPCR检测热激蛋白70（HSP70）的表达水平。结果显示，与低温处理及对照组相比，热激处理后HSP70的表达水平显著上调。最引人注目的是，近交强烈干扰了热激响应：近交个体仅表现出极微弱的HSP70上调现象。因此，本研究结果表明，在本实验对象中，热激响应受干扰或为近交个体适合度下降的潜在机制之一，尤其是当其暴露于胁迫环境时。不过，该结论仍需在更广泛的温度梯度、基因及分类群中进行验证。