Data from: Preadult life history variation determines adult transcriptome expression

Preadult determinants of adult fitness and behavior have been documented in a variety of organisms with complex life cycles, but little is known about expression patterns of genes underlying these adult traits. We explored the effects of differences in egg to adult development time on adult transcriptome and cuticular hydrocarbon variation in order to understand the nature of the genetic correlation between preadult development time and premating isolation between populations of Drosophila mojavensis reared in different host cactus environments. Transcriptome variation was analyzed separately in flies reared on each host and revealed that hundreds of genes in adults were differentially expressed (FDR P < 0.05) due to development time differences. For flies reared on pitaya agria cactus, longer preadult development times caused increased expression of genes in adults enriched for ribosome production, protein metabolism, chromatin remodeling, and regulation of alternate splicing and transcription. Baja California flies reared on organ pipe cactus showed fewer differentially expressed genes in adults due to longer preadult development time, but these were enriched for ATP synthesis and the TCA cycle. Mainland flies reared on organ pipe cactus with shorter development times showed increased transcription of genes enriched for mitochondria and energy production, protein synthesis, and glucose metabolism: adults with longer development times had increased expression of genes enriched for adult life span, cuticle proteins and ion binding, although most differentially expressed genes were unannotated. Differences due to population, sex, mating status, and their interactions were also assessed. Adult cuticular hydrocarbon profiles also showed shifts due to egg to adult development time, and were influenced by population and mating status. These results help to explain why preadult life history variation determines subsequent expression of the adult transcriptome along with traits involved with reproductive isolation and revealed previously undocumented connections between genetic and environmental influences over the entire life cycle in this desert insect.

已有研究在多种具有复杂生活史的生物中报道了成虫适合度与行为的成虫前期发育决定因子，但对于这些成虫性状背后的基因表达模式却知之甚少。本研究以不同寄主仙人掌环境中饲养的莫哈韦果蝇（Drosophila mojavensis）种群为对象，探究卵至成虫发育时长差异对成虫转录组（transcriptome）与表皮碳氢化合物（cuticular hydrocarbon）变异的影响，以阐明成虫前期发育时长与种群间交配前生殖隔离之间的遗传关联本质。研究分别对各寄主上饲养的果蝇开展转录组变异分析，结果显示，因发育时长差异，成虫体内数百个基因呈现显著差异表达（错误发现率P<0.05，False Discovery Rate, FDR）。对于以阿格里亚火龙果仙人掌（pitaya agria cactus）为寄主饲养的果蝇，更长的成虫前期发育时长会上调成虫体内与核糖体生成、蛋白质代谢、染色质重塑以及可变剪接与转录调控相关的富集基因的表达。以风琴仙人掌（organ pipe cactus）为寄主饲养的下加利福尼亚果蝇种群，其成虫因成虫前期发育时长延长而出现的差异表达基因数量更少，但这些基因显著富集于ATP合成与三羧酸循环（TCA cycle）通路。以风琴仙人掌为寄主饲养、发育时长较短的大陆果蝇种群，其成虫体内与线粒体及能量生成、蛋白质合成以及葡萄糖代谢相关的富集基因的转录水平上调；而发育时长较长的成虫体内，则上调了与成虫寿命、表皮蛋白及离子结合相关的富集基因的表达，不过多数差异表达基因未被注释。研究同时评估了种群、性别、交配状态及其交互作用带来的差异。成虫表皮碳氢化合物谱也因卵至成虫发育时长发生变化，同时受种群与交配状态的影响。本研究结果有助于解释成虫前期生活史变异如何决定成虫转录组的后续表达以及与生殖隔离相关的性状，并揭示了这种沙漠昆虫整个生命周期中遗传与环境影响之间此前未被记录的关联。