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 was reared under a single photoperiod (LD cycle 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. Nonoverlapping 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.

高纬度地区随季节更迭的环境对昆虫的繁殖与生存构成极大挑战，而光周期信号（photoperiodic cues）在帮助昆虫同步自身生命周期与当前及未来环境条件方面发挥着关键作用。我们对采自加拿大与芬兰不同纬度的蒙纳果蝇（Drosophila montana）种群，开展了光周期调控四项生活史性状的数量性状基因座（quantitative trait loci，QTL）定位分析，这四项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子代在单一光暗循环16:8（LD cycle 16:8）条件下饲养，该光周期会被加拿大种群果蝇识别为初夏，而芬兰种群果蝇则将其判定为夏末。分析结果显示，X染色体上存在一个独特的滞育诱导相关QTL，第4号染色体上则存在多个与该性状及其他被测性状相关的QTL。果蝇的耐寒性、卵至羽化发育时长以及幼虫体重还在第2、3、5号染色体上存在多个QTL，其中部分位点峰值存在重叠。这些结果表明，尽管在给定日照长度下，雌性光周期滞育响应的下游输出与其余性状的遗传调控机制存在部分差异，但所有性状也共享部分QTL，这可能涉及具有多效性效应的基因以及/或者多个紧密连锁的基因。针对部分性状检测到的非重叠QTL也提示，即便这些性状可能受上位性互作以及/或者性状间的相关性与权衡关系所限制，它们仍具备独立演化的潜力。