Effects of genetic factors and infection status on wing morphology of Triatoma dimidiata species complex in the Yucatán peninsula, Mexico

• Published in: Infection, genetics and evolution Vol. 11; no. 6; pp. 1243 - 1249
• Main Authors: Nouvellet, Pierre, Ramirez-Sierra, Maria Jesus, Dumonteil, Eric, Gourbière, Sébastien
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01-08-2011; Elsevier
• Subjects: Animals; Biodiversity and Ecology; Biological and medical sciences; Chagas disease; disease transmission; DNA, Ribosomal Spacer - genetics; ecology; Environmental Sciences; Epidemiology. Vaccinations; Female; females; gene flow; General aspects; Genetic Association Studies; Genetic Variation; Genotype; Human protozoal diseases; hybrids; Infectious diseases; insect development; internal transcribed spacers; loci; Male; males; Medical sciences; Mexico; Morphometry; Parasitic diseases; Protozoal diseases; sibling species; Triatoma - anatomy & histology; Triatoma - genetics; Triatoma - parasitology; Triatoma dimidiata; Triatomine; Trypanosoma cruzi; Trypanosoma cruzi - parasitology; Trypanosomiasis; Vector; villages; wings; Wings, Animal - anatomy & histology; Mexico; Central America; America; Chagas disease; Infectious diseases; Morphometry; Vector; Triatomine; Trypanosoma cruzi; Kinetoplastida; Protozoa; Protozoal disease; Parasitosis; Genetic determinism; Infection; Morphology; Molecular epidemiology; Trypanosomiasis
• ISSN: 1567-1348; 1567-7257
• DOI: 10.1016/j.meegid.2011.04.008

► In the Yucatán area, dispersal determines Triatoma dimidiata abundance in human habitat. ► We examine factors affecting the shape and size of triatomines’ wings. ► Females have larger and more symmetrical wings than males. ► Individuals infected with Trypanosoma cruzi have larger wings than non-infected ones. ► Sex and infection must be key determinants of vector dispersal and transmission.
Triatoma dimidiata is one of the main vectors of Chagas disease, and it has been shown to be a species complex. In the Yucatán peninsula, Mexico, vector populations are non-domiciliated, and the transmission of Trypanosoma cruzi thus critically relies on vector dispersal. This leads us to study the morphologic variations in T. dimidiata wings with respect to genetic factors (sex and genotype at the ITS-2 locus), geographic location, and T. cruzi-infection status. Females were found to have larger and more symmetrical wings than males. Wing shape was influenced by ITS-2 genotypes, although differences are unlikely sufficient to allow taxonomic discrimination of the sibling species. Hybrids were shown to have similar fluctuating asymmetries in wing size and shape as parental species, but the level of asymmetry in shape varied slightly between villages. The two later findings are consistent with a high level of gene flow between parental species, and the high dispersal potential of these non-domiciliated vectors. More surprisingly, individuals infected with T. cruzi were found to have larger wings than non-infected ones. This effect, which was consistently observed across sexes, genotypes and villages, is likely to be due to a direct impact of T. cruzi on insect development. Sex and infection status are thus likely to be key factors influencing vector dispersal with important impacts on disease transmission, since dispersal directly controls the domestic abundance of these vectors. These aspects should be investigated further to fully capture the ecology and evolution of Chagas disease transmission by non-domiciliated vectors.