Transcriptional variation associated with cactus host plant adaptation in Drosophila mettleri

Although the importance of host plant chemistry in plant–insect interactions is widely accepted, the genetic basis of adaptation to host plants is not well understood. Here, we investigate transcriptional changes associated with a host plant shift in Drosophila mettleri. While D. mettleri is distributed mainly throughout the Sonoran Desert where it specializes on columnar cacti (Carnegiea gigantea and Pachycereus pringleii), a population on Santa Catalina Island has shifted to chemically divergent coastal prickly pear cactus (Opuntia littoralis). We compared gene expression of larvae from the Sonoran Desert and Santa Catalina Island when reared on saguaro (C. gigantea), coastal prickly pear and laboratory food. Consistent with expectations based on the complexity and toxicity of cactus relative to laboratory food, within-population comparisons between larvae reared on these food sources revealed transcriptional differences in detoxification and other metabolic pathways. The majority of ...尽管寄主植物化学在植物-昆虫互作中的重要性已得到广泛认可，但针对寄主植物适应性的遗传基础仍未得到充分阐明。本研究以梅氏果蝇（Drosophila mettleri）为研究对象，探究其在寄主植物转换过程中的转录组变化。梅氏果蝇主要分布于索诺兰沙漠，专性寄生柱状仙人掌类（巨人柱<Carnegiea gigantea>与波棱掌<Pachycereus pringleii>）；而圣卡塔利娜岛上的一个种群已转换至化学组成差异显著的沿海梨果仙人掌（Opuntia littoralis）。我们对比了索诺兰沙漠种群与圣卡塔利娜岛种群的幼虫在分别取食巨人柱、沿海梨果仙人掌及实验室饲料时的基因表达水平。相较于实验室饲料，仙人掌的化学组成更为复杂且具有毒性，符合这一特征的种群内对比结果显示：取食不同食物的幼虫在解毒代谢及其他代谢通路中存在转录组差异。绝大多数……