Data from: Localization of QTL for diapause and other photoperiodically regulated life-history traits important in adaptation to seasonally varying environments

Seasonally changing environments at high latitudes present great challenges for the reproduction and survival of insects, and photoperiodic cues play an important role in helping them to synchronize their life cycle with prevalent and forthcoming conditions. We have mapped quantitative trait loci (QTL) responsible for the photoperiodic regulation of four life-history traits, female reproductive diapause, cold tolerance, egg-to-eclosion development time and juvenile body weight in Drosophila montana strains from different latitudes in Canada and Finland. The F2 progeny of the cross were reared under a single photoperiod (LD 16:8), which the flies from the Canadian population interpret as early summer and the flies from the Finnish population as late summer. The analysis revealed a unique QTL for diapause induction on the X-chromosome and several QTL for this and the other measured traits on the 4th chromosome. Flies’ cold tolerance, egg-to-eclosion development time and juvenile body weight had several QTL also on the 2nd, 3rd and 5th chromosome, some of the peaks overlapping with each other. These results suggest that, while the downstream output of females’ photoperiodic diapause response is partly under a different genetic control from that of the other traits in the given day length, all traits also share some QTL, possibly involving genes with pleiotropic effects and/or multiple tightly linked genes. Non-overlapping QTL detected for some of the traits also suggest that the traits are potentially capable of independent evolution, even though this may be restricted by epistatic interactions and/or correlations and trade-offs between the traits.高纬度地区的季节性变化环境对昆虫的繁殖与生存构成严峻挑战，而光周期信号（photoperiodic cues）在协助昆虫将自身生命周期与当下及未来的环境条件同步方面发挥着关键作用。本研究对取自加拿大与芬兰不同纬度的山果蝇（Drosophila montana）品系展开分析，定位了调控四种生活史性状的光周期相关数量性状位点（quantitative trait loci, QTL），这四种性状分别为雌性生殖滞育、耐寒性、卵至羽化发育时长以及幼虫体重。杂交获得的F2子代在单一光暗周期（LD 16:8）下饲养，该光周期对加拿大种群的果蝇而言相当于初夏，而对芬兰种群的果蝇则相当于夏末。分析结果显示，X染色体上存在一个调控滞育诱导的独特QTL，而4号染色体上则存在多个调控该性状及其他被测性状的QTL。果蝇的耐寒性、卵至羽化发育时长与幼虫体重在2号、3号及5号染色体上也存在多个QTL，其中部分峰值存在重叠。上述结果表明，尽管在给定日照长度下，雌性光周期滞育反应的下游产出与其他性状的遗传调控存在部分差异，但所有性状仍共享部分QTL，这可能涉及具有多效性效应的基因以及（或）多个紧密连锁的基因。部分性状检测到的非重叠QTL也提示，即便这些性状的独立演化可能受上位性互作以及（或）性状间的相关性与权衡关系所限制，各性状仍具备独立演化的潜力。