Genetics and evolution of triatomines: from phylogeny to vector control

Abstract

Triatomines are hemipteran bugs acting as vectors of the protozoan parasite Trypanosoma cruzi. This parasite causes Chagas disease, one of the major parasitic diseases in the Americas. Studies of triatomine genetics and evolution have been particularly useful in the design of rational vector control strategies, and are reviewed here. The phylogeography of several triatomine species is now slowly emerging, and the struggle to reconcile the phenotypic, phylogenetic, ecological and epidemiological species concepts makes for a very dynamic field. Population genetic studies using different markers indicate a wide range of population structures, depending on the triatomine species, ranging from highly fragmented to mobile, interbreeding populations. Triatomines transmit T. cruzi in the context of complex interactions between the insect vectors, their bacterial symbionts and the parasites; however, an integrated view of the significance of these interactions in triatomine biology, evolution and in disease transmission is still lacking. The development of novel genetic markers, together with the ongoing sequencing of the Rhodnius prolixus genome and more integrative studies, will provide key tools to expanding our understanding of these important insect vectors and allow the design of improved vector control strategies.

House Infestation Dynamics and Feeding Sources of Triatoma dimidiata in Central Veracruz, Mexico

“…In fact, T. dimidiata is one of the major vectors of Chagas disease, with an extensive geographic distribution ranging from the northern part of South America, through Central America, and to Southern Mexico. 7,8 It is also a very diverse species in terms of its morphology, genetics, adaptation to diverse habitats, and ability to feed on a wide diversity of veterbrate hosts. For example, as mentioned previously, T. dimidiata seems well domiciliated in Veracruz and central Mexico, 5 although it seasonally infests houses in the Yucatan peninsula, Mexico, 9,10 and in Belize.…”

Within-host competition and diversification of macro-parasites

“…There are also more and more studies revealing the importance and variety of ecological interactions between parasites at the scale of the host body [8,9], including competition [10], facilitation by immuno-suppression [11] and inhibition by the elicitation of non-specific immune response [12]. With the concurrent theoretical and empirical realization that biotic interactions can lead to adaptive diversification in plants [13], fungi [14], algae [15], fishes [16] and various other taxa [17], one expects more adaptive duplication events to be reported as more attention would be given to this overlooked source of parasite diversity.…”

The Quest for Immortality in Triatomines: A Meta-Analysis of the Senescence Process in Hemimetabolous Hematophagous Insects

“…Most studies in triatomines have investigated physiology, population genetics, phylogeny (see Gourbière et al, 2011 for a review) and ecology of a given species (e.g., Dumonteil et al, 2002;Gourbière et al, 2008;Barbu et al, 2011) but very few studies have investigated the evolution of life history traits in the light of evolutionary ecology concepts (Menu et al, 2010). Our study is the first comparative analysis to the senescence pattern and its relationship with life history traits in triatomines.…”