Gene expression of young, middle-aged and old Drosophila melanogaster exposed to different levels of larval and adult diet. Drosophila melanogaster

Many studies have addressed the effects of adult diet on gene expression in Drosophila melanogaster, however, little is known about how developmental diet influences adult gene expression, and how this interacts with adult dietary conditions. We found that developmental and adult diet exert largely independent effects on gene expression, with the effect of adult diet being considerably larger.We did find effects of developmental diet on the transcriptome that persist into middle and old-age. Most of the genes affected show no correlation with the observed phenotypic effects of larval diet on lifespan, however, in each sex we identified a cluster of ribosome, transcription, and translation-related genes whose expression was altered across the lifespan and negatively correlated with lifespan. Overall design: We raised flies as larvae on three different diets and switched them across these same diets as adults, using a fully factorial design (3 larval * 3 adult diets = 9 treatments in total). We measured gene expression in both sexes at 1 day post-eclosion, middle-age (10% cohort mortality) and old-age (90% cohort mortality).

已有诸多研究针对成年饮食对黑腹果蝇（Drosophila melanogaster）的基因表达影响展开了探究，但目前学界对发育阶段日粮如何调控成虫基因表达，以及其与成虫膳食条件间的互作机制仍知之甚少。本研究发现，发育阶段与成虫饮食对基因表达的影响大体相互独立，且成虫饮食的影响幅度显著更大。同时我们也观测到，发育阶段日粮对转录组（transcriptome）的影响会持续至中年与老年阶段。受影响的绝大多数基因与幼虫日粮对寿命产生的已知表型效应并无关联，但我们在每个性别中均鉴定出了一类与核糖体、转录及翻译相关的基因簇，其表达水平随寿命进程发生改变，且与寿命呈负相关。

实验总体设计：我们将果蝇幼虫饲养于三种不同的日粮中，并在成虫阶段将其转移至这三种日粮中进行交叉处理，采用完全析因设计（3种幼虫日粮 × 3种成虫日粮，共计9个处理组）。我们分别在羽化后1天、中年（队列死亡率达10%）以及老年（队列死亡率达90%）三个时间点，对雌雄果蝇的基因表达水平进行了检测。