Daily Variations in the Expression of Genes Related to Insecticide Resistance in the Chagas Disease Vector Triatoma infestans (Hemiptera: Reduviidae).

Pyrethroid resistance has been detected in Triatoma infestans, which in part has been attributed to increased oxidative metabolism of the insecticide by cytochrome P450s. Nicotinamide adenine dinucleotide phosphate (NADPH) cytochrome P450 reductase (CPR) catalyzes electron transfer from NADPH to all known cytochrome P450s. In this study, the expression of the CPR gene at transcriptional level was determined in different tissues and two life stages. The expression patterns showed differences in the tissues and stages studied, suggesting differential metabolic requirements. On the other hand, to investigate the presence of rhythms in the expression of genes related with insecticide resistance, we explored the daily expression profile of the CPR gene and a P450 gene (CYP4EM7) in fat body from adults of T. infestans under different dark/light regimes. The results suggest that CPR gene expression is under endogenous clock regulation and show a rhythmic profile in the expression of the CYP4EM7 gene.