Tyraminergic signalling pathway is involved in regulating egg production in the Chagas disease vector Rhodnius prolixus

Sunday, November 13, 2022

10:24 AM – 10:36 AM PT

Location: Vancouver Convention Centre, Meeting Room 111/112

Presenting Author(s)

LF

Luca Finetti

Post Doctoral Research
University of Toronto
Mississauga, Ontario, Canada

Co-Author(s)

IO

Ian Orchard

University of Toronto
Mississauga, Ontario, Canada
AL

Angela B. Lange

University of Toronto
Mississauga, Ontario, Canada

In insects, the biogenic amine tyramine (TA) has been shown to control several physiological processes. Recently, the involvement of the type 1 tyramine receptor (TAR1) in reproductive processes has been demonstrated in several insects. Here, we investigate the putative role of Rhodnius prolixus TAR1 (RpTAR1) in egg development in the Chagas disease vector, R. prolixus.RpTAR1 transcript was highly expressed in tissues associated with egg development in the unfed female. Moreover, after a blood meal, RpTAR1 transcript was upregulated in ovaries and in fat body; the latter suggesting that TA might be involved in vitellogenin synthesis. After RNAi-mediated RpTAR1 silencing, an ovarian phenotype characterized by reduced egg production was observed. Furthermore, protein accumulated in the fat body with a concomitant reduced uptake by the ovaries, suggesting an impairment in protein release from the fat body. However, even though less eggs were produced and laid, there was no difference in hatching ratio in comparison to the controls, indicating that the overall low protein uptake by ovaries did not influence the viability of the eggs. We also observed transcript variations of the main actors involved in the ecdysone and juvenile hormone pathways, suggesting an interplay between TA and other important pathways controlling reproduction. These results provide critical information concerning the role of TAR1 in egg production in R. prolixus. Furthermore, considering the emerging role of TAR1 as a target for pest control, this work opens the way for further investigation into innovative methods for controlling R. prolixus.