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极大挑战，而光周期线索（photoperiodic cues）在帮助昆虫同步其生命周期以适配当前及未来环境条件方面发挥着关键作用。本研究对加拿大与芬兰不同纬度地区的山果蝇（Drosophila montana）品系展开分析，定位了调控四种生活史性状光周期响应的数量性状基因座（quantitative trait loci，QTL），这四种性状分别为雌性生殖滞育、耐寒性、卵至成虫发育时长以及幼虫体重。本杂交组合的F2子代在单一光周期（LD 16:8）条件下饲养，该光周期对加拿大种群果蝇而言相当于初夏，对芬兰种群果蝇而言则相当于夏末。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，而第4号染色体上则存在多个与该滞育性状及其他被测性状相关的QTL。果蝇的耐寒性、卵至成虫发育时长以及幼虫体重在第2、3、5号染色体上也存在多个QTL，其中部分QTL峰值存在重叠。上述结果表明：尽管在该设定光周期条件下，雌性果蝇光周期滞育响应的下游效应在遗传调控上与其他三种性状存在部分差异，但所有四种性状共享部分QTL，这些QTL可能涉及具有多效性的基因，或是多个紧密连锁的基因。部分性状所检测到的非重叠QTL也表明，这些性状具备独立演化的潜力，尽管这一潜力可能会受到上位性互作、性状间相关关系及权衡关系的限制。