Lectin Recognition Patterns in the Gut of Meccus (Triatoma) pallidipennis and Their Association with Trypanosoma cruzi Metacyclogenesis.

The successful transmission of Trypanosoma cruzi, the causative agent of Chagas disease, depends on intricate interactions with its insect vector. In Mexico, Meccus pallidipennis is a relevant triatomine species involved in the parasite's life cycle. In the gut of these insects, the parasite moves from the anterior midgut (AMG) to the posterior midgut (PMG), where it multiplies. Finally, T. cruzi differentiates into its infective form by metacyclogenesis in the proctodeum or rectum (RE). This study aimed to characterize and compare the protein and glycoprotein profiles of the anterior midgut (AMG) and rectum (RE) of M. pallidipennis, and to assess their potential association with T. cruzi metacyclogenesis, with special attention to sex-specific differences. Insects were infected with the T. cruzi isolate ITRI/MX/12/MOR (Morelos). Protein profiles were analyzed by polyacrylamide gel electrophoresis, while glycoproteins were detected using ConA, WGA, and PNA lectins. The metacyclogenesis index was calculated for male and female triatomines. A lower overlap of protein fractions was found in the RE compared to the AMG between sexes, suggesting functional sexual dimorphism. Infected females showed greater diversity in glycoprotein patterns in the RE, potentially related to higher blood intake and parasite burden. The metacyclogenesis index was significantly higher in females than in males. These findings highlight sex-dependent differences in gut protein and glycoprotein profiles in M. pallidipennis, which may influence the efficiency of T. cruzi development within the vector. Further proteomic studies are needed to identify the molecular components involved and clarify their roles in parasite differentiation and suggest new targets for disrupting parasite transmission within the vector.