As apolipoproteínas e seu papel na fisiologia reprodutiva de Rhodnius prolixus, um vetor da doença de Chagas

Abstract

The triatomine Rhodnius prolixus is an important vector of the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease, and one of the main model organisms for studies on the physiology of blood-feeding insects. In recent years, apolipoproteins belonging to the lipocalin family have been described in this species, but their functions have not yet been elucidated. Considering their high expression in testes and evidence of lipocalin involvement in reproductive processes in other organisms, this thesis investigated the role of the apolipoproteins RPRC010099 and RPRC015421 in the reproductive physiology of R. prolixus. Genomic and molecular modeling analyses were performed to characterize the structure and putative function of RPRC010099 and RPRC015421. Basal gene expression of RPRC010099 and RPRC015421 in reproductive organs of R. prolixus were quantified. Using RNAi, the genes RPRC010099 and RPRC015421 were silenced in male insects to evaluate their effects on reproduction. Finally, recombinant proteins and polyclonal antibodies were produced to assess the transfer of RPRC010099 and RPRC015421 from males to females during copulation. In silico analyses confirmed the identity of these proteins as lipocalins and suggested affinity for lipid molecules, especially eicosanoids such as prostaglandin E2 (PGE2) and eicosapentaenoic acid (EPA). Gene expression was significantly higher in testes, with differential patterns between males and females. RNAi-mediated gene silencing resulted in reduced insect fertility, evidenced by a decrease in the number of eggs laid, without affecting hatching rates. Transfer assays revealed that both apolipoproteins studied are transferred from males to females during copulation. Altogether, the results indicate that apolipoproteins RPRC010099 and RPRC015421 act as male reproductive factors, possibly carrying eicosanoids during copulation and modulating female fertility. This study expands the understanding of reproductive physiology in triatomines, highlighting the relevance of male factors in species fertility and suggesting new molecular targets for strategies aimed at controlling R. prolixus populations and, consequently, the transmission of Chagas disease.