Different roles of protein coding genes and microRNAs in response to environmental changes during insect sex evolution

Different sexes of the same species exhibit biological and physiological differences in addition to their sex organs. Despite the important roles of sex-biased genes which are now better elucidated in humans and other vertebrates, how they function in insects, especially in the context of sex-biased microRNAs in response to environmental cues, are poorly understood. Here, we utilised four species of fruit flies Drosophila (D. melanogaster, D. virilis, D. pseudoobscura, and D. erecta), and revealed 144 transcriptomic profiles of protein coding gene and microRNA in both sexes exposed to three different temperatures. More male-biased than female-biased protein-coding genes and microRNAs were revealed in all four insect species at the same temperature. Upon temperature changes, we nevertheless discovered that there were more differentially expressed protein-coding genes in females than males in all four investigated species, while the microRNAs behaved differently between sexes and species. This study provides the first evidence that different selection forces act on protein coding genes and microRNAs upon environmental changes during insect sex evolution.