Can insecticide resistance alter behaviour and fitness by modifying the gut microbiome?

Resistance to a range of insecticides is conferred by upregulation of the cytrochrome P450 gene Cyp6g1 in Drosophila melanogaster, and has been associated with sex-specific pleiotropic effects on behaviour and fitness. Cyp6g1 is primarily overexpressed in the gut in insecticide resistant individuals and metabolises a large range of molecules, and thus upregulation may alter the gut environment and the community composition of the gut microbiota. The community composition of gut microbiota can have profound effects on behaviour and fitness, and if Cyp6g1 expression can explain differences in gut microbiota then it may help explain its observed fitness effects. Comparing microbial community composition between the guts of insecticide resistant and susceptible individuals (high and low Cyp6g1 expression, respectively) via 16s rRNA sequencing would be the first necessary experiment to demonstrate that insecticide resistance can alter behaviour and fitness by modifying the gut microbiome.

黑腹果蝇（Drosophila melanogaster）体内的细胞色素P450（cytochrome P450）基因Cyp6g1上调，可赋予其对多种杀虫剂的抗性，且该现象与行为、生存适合度的性别特异性多效性效应相关。在杀虫剂抗性个体中，Cyp6g1主要在肠道内过度表达，能够代谢多种分子，因此该基因的上调可能改变肠道微环境与肠道微生物群（gut microbiota）的群落组成。肠道微生物群的群落组成对行为与生存适合度具有显著影响，若Cyp6g1的表达水平能够解释肠道微生物群的差异，则有望阐明该基因对适合度产生的已知效应。通过16S rRNA测序技术，对比杀虫剂抗性与敏感个体（分别对应Cyp6g1高、低表达水平）的肠道微生物群落组成，是验证"杀虫剂抗性可通过改变肠道微生物组（gut microbiome）调控行为与生存适合度"的首个必要实验。