"Daily Variations In The Expression Of Genes Related To Insecticide Resistance And Molecular Bases Of The Biological Clock In Triatoma Infestans

STROPPA MM; VARELA GM; GARCIA BA

Congreso; Reunión Anual SAIB, SAFE, SAB, SAP; 2019

Triatoma infestans present rhythms in diverse biological processes. Previous studies in the expression of the genes cytochromes P450 and NADPH cytochrome P450 reductase (CPR) revealed that P450 genes would be involved in the development of resistance to insecticides in T. infestans. To investigate the presence of rhythms in the expression of genes related to insecticide resistance, we explored the daily expression of CPR gene and a P450 gene (CYP4EM7) in fat body of groups of T. infestans maintained under light/dark cycle (LD), constant light (LL), and constant dark (DD). On the other hand, to better understand the molecular bases of the biological clock, we analysed the expression at mRNA level of the clock genes period (per) and timeless (tim). In LD, the CPR gene expression profile of females showed two peaks, conserved in DD and lost in LL, that suggest the CPR expression is under endogenous clock regulation. In contrast, in males was not observed a rhythmic profile in the expression of the CPR gene. In LD, the expression of CYP4EM7 gene showed daily significant variations. Females presented a peak at dawn and males showed two peaks, one at dawn and other at sunset. The per and tim genes expression in nervous tissue of adults T. infestans varies with a daily rhythm in LD, showing a significant peak at sunset. These rhythms agrees with those described in Drosophila melanogaster and would promote a peak of PER and TIM protein levels at night. As expected, in LL no daily increase was detected in per and tim transcript levels. Besides, the presence of per transcript in different tissues of adult individuals and in nervous tissue of nymphs evidenced activity of peripheral clocks in adults and activity of the central clock in nymphs of T. infestans. Studies of circadian rhythms in insecticide resistance and their molecular basis could contribute to develop of new control strategies for T. infestans populations.