Lindestad Olle, Nylin Sören, Wheat Christopher W, Gotthard Karl
Department of Ecology, Environment and Plant Sciences Stockholm University Stockholm Sweden.
Department of Zoology Stockholm University Stockholm Sweden.
Ecol Evol. 2024 Jul 7;14(7):e11713. doi: 10.1002/ece3.11713. eCollection 2024 Jul.
The genetic components of the circadian clock have been implicated as involved in photoperiodic regulation of winter diapause across various insect groups, thereby contributing to adaptation to adverse seasonal conditions. So far, the effects of within-population variation in these genes have not been well explored. Here, we present an experimental test of the effects of within-population variation at two circadian genes, and , on photoperiodic responses in the butterfly . While nonsynonymous candidate SNPs in both of these genes have previously shown to be associated with diapause induction on a between-population level, in the present experiment no such effect was found on a within-population level. In trying to reconcile these results, we examine sequence data, revealing considerable, previously unknown protein-level variation at both and across Scandinavian populations, including variants unique to the population studied here. Hence, we hypothesize that these variants may counteract the previously observed diapause-averting effect of the candidate SNPs, possibly explaining the difference in results between the experiments. Whatever the cause, these results highlight how the effects of candidate SNPs may sometimes vary across genetic backgrounds, which complicates evolutionary interpretations of geographic patterns of genetic variation.
生物钟的遗传成分已被认为参与了各类昆虫群体冬季滞育的光周期调控，从而有助于适应不利的季节条件。到目前为止，这些基因在种群内变异的影响尚未得到充分研究。在此，我们对蝴蝶中两个生物钟基因的种群内变异对光周期反应的影响进行了实验测试。虽然之前已表明这两个基因中的非同义候选单核苷酸多态性（SNPs）在种群间水平上与滞育诱导有关，但在本实验中，在种群内水平上未发现此类效应。为了协调这些结果，我们检查了序列数据，发现斯堪的纳维亚种群中这两个基因在蛋白质水平上都存在相当大的、此前未知的变异，包括此处研究种群特有的变体。因此，我们推测这些变体可能会抵消之前观察到的候选SNPs的避免滞育效应，这可能解释了实验结果之间的差异。无论原因如何，这些结果凸显了候选SNPs的效应有时可能因遗传背景而异，这使得对遗传变异地理模式的进化解释变得复杂。
