Interactive Effects of Previous and Current Thermal Conditions on Gene Expression in Manduca sexta

This study performed RNA sequencing of fat body tissue from two populations of the tobacco hornworm caterpillar (Manduca sexta): a UNC-maintain laboratory colony and field population collected from eastern NC. The objective of this investigation was to evaluate the effects of diurnal temperature fluctuations (of 30 plus and minus 0, 5, or 10 degrees C) throughout development on larval gene expression both independently and in conjunction with subsequent thermal exposure (of 30, 35, or 40 degrees C). Results from differential expression analyses of these data highlight large differences in overall gene expression patterns between these two populations (across all temperature treatments) as well as population-specific transcriptomic responses to temperature. Exposure to fluctuating temperatures during rearing did alter gene expression during later heat stress in some cases, but this effect depended upon both the population and the specific temperature conditions. This research contributes to increased knowledge of molecular mechanisms underlying physiological responses of organisms to temperature, particularly with respect to thermal plasticity and adaptation in populations with different evolutionary histories.

本研究对两个种群的烟草天蛾（Manduca sexta）幼虫脂肪体组织开展了RNA测序（RNA sequencing），两个种群分别为：由UNC维持的实验室种群，以及采自美国北卡罗来纳州东部的野外种群。本研究的目标为评估：在昆虫整个发育周期内，以30℃为基准、波动幅度为±0、±5或±10℃的昼夜温度波动，对幼虫基因表达的单独效应，以及其与后续热暴露（30、35或40℃）的联合效应。对上述数据进行差异表达分析的结果显示，两个种群在所有温度处理下的整体基因表达模式均存在显著差异，且二者对温度的转录组响应具有种群特异性。部分实验中，饲养阶段的波动温度暴露会改变后续热胁迫过程中的幼虫基因表达，但该效应同时取决于种群类型与具体温度条件。本研究有助于加深对生物体温度响应生理过程背后分子机制的认知，尤其是针对具有不同进化历史的种群，其热可塑性与温度适应相关的分子机制。