Revisiting the development of Trypanosoma rangeli in the vertebrate host.

Background: Trypanosoma rangeli is a haemoflagellate parasite that infects triatomine bugs and mammals in South and Central America. Trypanosoma cruzi, the etiological agent of Chagas disease, has a partially overlapping geographical distribution with T. rangeli, that leads to mixed human infections and cross-reactivity in immunodiagnosis.

Local age-dependent neuromodulation in Rhodnius prolixus antennae.

Kissing bugs do not respond to host cues when recently molted and only exhibit robust host-seeking several days after ecdysis. Behavioral plasticity has peripheral correlates in antennal gene expression changes through the week after ecdysis. The mechanisms regulating these peripheral changes are still unknown, but neuropeptide, G-protein coupled receptor, nuclear receptor, and takeout genes likely modulate peripheral sensory physiology.

The antennal transcriptome of Triatoma infestans reveals substantial expression changes triggered by a blood meal.

Background: Triatoma infestans is the main vector of Chagas disease in the Americas, currently transmitting it in Argentina, Paraguay, and Bolivia. Many T. infestans populations present insecticide resistance, reducing the efficiency of control campaigns.

Changes in antennal gene expression underlying sensory system maturation in Rhodnius prolixus.

Triatomine bugs are the blood feeding insect vectors transmitting Chagas disease to humans, a neglected tropical disease that affects over 8 million people, mainly in Latin America. The behavioral responses to host cues and bug signals in Rhodnius prolixus are state dependent, i.e.

Trypanosoma cruzi-infected Rhodnius prolixus endure increased predation facilitating parasite transmission to mammal hosts.

Triatomine bugs aggregate with conspecifics inside shelters during daylight hours. At dusk, they leave their refuges searching for hosts on which to blood feed. After finding a host, triatomines face the threat of being killed, because hosts often prey on them.

Co-existing locomotory activity and gene expression profiles in a kissing-bug vector of Chagas disease.

The triatomine bug Rhodnius prolixus is a main vector of Chagas disease, which affects several million people in Latin-America. These nocturnal insects spend most of their locomotory activity during the first hours of the scotophase searching for suitable hosts. In this study we used multivariate analysis to characterize spontaneous locomotory activity profiles presented by 5th instar nymphs.

Transcriptomics supports local sensory regulation in the antenna of the kissing-bug Rhodnius prolixus.

Background: Rhodnius prolixus has become a model for revealing the molecular bases of insect sensory biology due to the publication of its genome and its well-characterized behavioural repertoire. Gene expression modulation underlies behaviour-triggering processes at peripheral and central levels. Still, the regulation of sensory-related gene transcription in sensory organs is poorly understood.

The molecular sensory machinery of a Chagas disease vector: expression changes through imaginal moult and sexually dimorphic features.

The triatomine bug Rhodnius prolixus is a main vector of Chagas disease, which affects several million people, mostly in Latin-America. Host searching, pheromone communication, and microclimatic preferences are aspects of its behaviour that depend on multimodal sensory inputs. The molecular bases of these sensory processes are largely unknown.

Triatomine physiology in the context of trypanosome infection.

Triatomines are hematophagous insects that feed on the blood of vertebrates from different taxa, but can occasionally also take fluids from invertebrate hosts, including other insects. During the blood ingestion process, these insects can acquire diverse parasites that can later be transmitted to susceptible vertebrates if they complete their development inside bugs. Trypanosoma cruzi, the etiological agent of Chagas disease, and Trypanosoma rangeli are protozoan parasites transmitted by triatomines, the latter only transmitted by Rhodnius spp.

Colonization of Rhodnius prolixus gut by Trypanosoma cruzi involves an extensive parasite killing.

Trypanosoma cruzi, the etiological agent of Chagas disease, is ingested by triatomines during their bloodmeal on an infected mammal. Aiming to investigate the development and differentiation of T. cruzi inside the intestinal tract of Rhodnius prolixus at the beginning of infection we fed insects with cultured epimastigotes and blood trypomastigotes from infected mice to determine the amount of recovered parasites after ingestion.

Trypanosomes Modify the Behavior of Their Insect Hosts: Effects on Locomotion and on the Expression of a Related Gene.

Background: As a result of evolution, the biology of triatomines must have been significantly adapted to accommodate trypanosome infection in a complex network of vector-vertebrate-parasite interactions. Arthropod-borne parasites have probably developed mechanisms, largely still unknown, to exploit the vector-vertebrate host interactions to ensure their transmission to suitable hosts. Triatomines exhibit a strong negative phototaxis and nocturnal activity, believed to be important for insect survival against its predators.

Patterns of expression of odorant receptor genes in a Chagas disease vector.

Rhodnius prolixus is a triatomine bug acting as a relevant vector of Chagas disease for which the genome sequence has been recently made available. Based on this information, a set of olfactory (ORs) and ionotropic receptor (IRs) genes potentially related to olfactory processes was characterized, and the expression patterns along bug development and in different structures potentially involved in promoting chemosensory-mediated behaviors were studied. For this, diverse bioinformatic procedures were used to validate gene models analyzing their structural and functional features and designing specific primers.

Effects of infection by Trypanosoma cruzi and Trypanosoma rangeli on the reproductive performance of the vector Rhodnius prolixus.

The insect Rhodnius prolixus is responsible for the transmission of Trypanosoma cruzi, which is the etiological agent of Chagas disease in areas of Central and South America. Besides this, it can be infected by other trypanosomes such as Trypanosoma rangeli. The effects of these parasites on vectors are poorly understood and are often controversial so here we focussed on possible negative effects of these parasites on the reproductive performance of R.

Behavioural biology of Chagas disease vectors.

Many arthropod species have adopted vertebrate blood as their main food source. Blood is rich in nutrients and, except for the presence of parasites, sterile. However, this food source is not freely available, nor is obtaining it devoid of risk.

Lack of segregation between two species of Chagas disease vectors.

Triatoma infestans and Panstrongylus megistus are relevant Chagas disease vectors. An apparent segregation among these triatomine species inside human households was suggested to rely on mutual repellence between them. However, P.

Influence of the palm tree species on the variability of Rhodnius nasutus Stål, 1859 (Hemiptera, Reduviidae, Triatominae).

This work evaluated the occurrence and genetic structure of Rhodnius nasutus sampled in two sites using morphometry and microsatellites. These sites, presented distinct abiotic features and palm trees: (i) nine Attalea speciosa palm trees, so called babaçu, were sampled from the Meruoca Mountain Ridge, a sloping region of reminiscent forest in the state of Ceará, Brazil, and (ii) 17 Copernicia prunifera palm trees, so called carnaúba, were sampled in the scrub savanna region (Sobral district) that surrounds the mountain ridge. Of the twenty-six palm trees dissected, 70.

Analysis of the geographical distribution of Triatoma vitticeps (Stål, 1859) based on data of species occurrence in Minas Gerais, Brazil.

The purpose of this study was to determine the potential for infestation of man-made environments by Triatoma vitticeps, correlating the epidemiological importance of this species with that of others present in the Brazilian state of Minas Gerais. In addition, climatic variables that could help explain the distribution of this species and clarify its population dynamics were sought. This was done by carrying out a historical survey of the presence of T.

The sexual behaviour of Panstrongylus megistus (Hemiptera: Reduviidae): an experimental study.

The factors affecting the sexual behaviour of Panstrongylus megistus were studied under laboratory conditions. A general description of mating behaviour is presented for this species. The effect of the time elapsed after the first imaginal feeding on the mating frequency, the motivation of males to mate and the rejection behaviour by females, were analyzed.