Rhodnius

Within insects, corticotropin-releasing factor/diuretic hormones (CRF/DHs) are responsible for the modulation of a range of physiological and behavioural processes such as feeding, diuresis, and reproduction. Rhopr-CRF/DH plays a key role in feeding and diuresis in Rhodnius prolixus , a blood-gorging insect and a vector for human Chagas disease. Here, we extend our understanding on the role of this neurohormone in reproduction in adult female R. prolixus . Double-label immunohistochemistry displays co-localized staining of CRF-like and the glycoprotein hormone (GPA2/GPB5) subunit GPB5-like immunoreactivity in the same neurosecretory cells (NSCs) in the mesothoracic ganglionic mass (MTGM) and in their neurohemal sites in adult female R...

During its life cycle, Trypanosoma rangeli invades the hemolymph of its invertebrate host and colonizes hemocytes and salivary glands. The parasite cannot synthesize some lipid classes, and during its cycle, it depends on the uptake of these molecules from its vertebrate and invertebrate hosts to meet growth and differentiation requirements. However, until now, knowledge on how the parasite affects the lipid physiology of individual insect organs has been largely unknown. Herein, the biochemical and molecular dynamics of triatomine R...

BACKGROUND: An external quality assessment on the identification of triatomines within the laboratory network in the state of Rondônia. METHODS: Seven laboratories participated in this evaluation. Each was provided with support materials and nine insects from the Hemiptera order for identification. RESULTS: All samples were accurately identified at the species level. However, correct sex identification was achieved for only 79% of the samples...

Water is essential to life. Terrestrial insects lose water by evaporation from the body surface and respiratory surfaces, as well as in the excretory products, posing a challenge made more acute by their high surface-to-volume ratio. These losses must be kept to a minimum and be offset by water gained from other sources. By contrast, insects such as the blood-sucking bug Rhodnius prolixus consume up to 10 times their body weight in a single blood meal, necessitating rapid expulsion of excess water and ions...

The blood-sucking hemipteran Rhodnius prolixus is one of the main vectors of Chagas disease, a neglected tropical disease that affects several million people worldwide. Consuming a blood meal and mating are events with a high epidemiological impact since after each meal, mated females can lay fertile eggs that result in hundreds of offspring. Thus, a better knowledge of the control of R. prolixus reproductive capacity may provide targets for developing novel strategies to control vector populations, thereby reducing vector-host contacts and disease transmission...

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The growing interest in microRNAs (miRNAs) over recent years has led to their characterization in numerous organisms. However, there is currently a lack of data available on miRNAs from triatomine bugs (Reduviidae: Triatominae), which are the vectors of the protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease. A comprehensive understanding of the molecular biology of vectors provides new insights into insect-host interactions and insect control approaches, which are key methods to prevent disease incidence in endemic areas...

Allatotropin (AT) acts as a myoregulator at the level of the dorsal vessel (DV) and midgut (MG) in triatominae insects. Previous analyses of the expression of the AT receptor in Rhodnius prolixus showed that AT is expressed in the DV and MG, but also in the reproductive system in females. To further study the activity of AT on female reproductive organs we analyzed the response by adult females in different physiological conditions, including unfed (virgin and mated), and fed mated females (gravid), to doses ranging between 10-14 and 10-6 M...

Introduction: Rhodnius prolixus (Hemiptera: Reduviidae) is an important vector of Trypanosoma cruzi , the causative agent of Chagas Disease. This insect is a model for the study of insect physiology, especially concerning the digestion of blood. Among the enzymes produced in the midgut of R. prolixus after blood feeding there is a α-L-fucosidase activity. There are very few studies on α-L-fucosidase of insects, and the role of R. prolixus α-L-fucosidase is still not clear. In this work, we tested if the mechanism for production of this enzyme is similar to the observed for proteases, a secretatogue mechanism that respond to the protein contents of the meal...

Autophagy and the ubiquitin-proteasome system (UPS) are important cellular mechanisms that coordinate protein degradation essential for proteostasis. P62/SQSTM1 is a receptor cargo protein able to deliver ubiquitinated targets to the proteasome proteolytic complex and/or to the autophagosome. In the insect vector of Chagas disease, Rhodnius prolixus, previous works have shown that the knockdown of different autophagy-related genes (ATGs) and ubiquitin-conjugating enzymes resulted in abnormal oogenesis phenotypes and embryo lethality...

The energy stored in fatty acids is essential for several critical activities of insects, such as embryogenesis, oviposition, and flight. Rhodnius prolixus is an obligatory hematophagous hemipteran and vector of Chagas disease, and it feeds infrequently on very large blood meals. As digestion slowly occurs, lipids are synthesized and accumulate in the fat body, mainly as triacylglycerol, in lipid droplets. Between feeding bouts, proper mobilization and oxidation of stored lipids are crucial for survival, and released fatty acids are oxidized by mitochondrial β-oxidation...

Trypanosoma rangeli is a protozoan parasite that infects triatomines and mammals in the Americas, producing mixed infections with Trypanosoma cruzi, the etiological agent of Chagas disease. The former parasite is not pathogenic to humans, but has different levels of pathogenicity, as well as causing physiological and behavioral alterations, to its invertebrate hosts. In this study, we measured locomotory activity, and the glyceride accumulation profile in the hemolymph and fat body, as well as the expression of key genes related to triglyceride metabolism, of Rhodnius prolixus nymphs infected with T...

Dorsal-ventral (DV) patterning is regulated by the bone morphogenetic pathway (BMP) in Bilateria. In insect DV patterning, the Toll pathway also plays a role, in addition to BMPs. Variations in the relative importance of each pathway for DV patterning have been reported using single species of coleopteran, hymenopteran, hemipteran and orthopteran insects. To investigate if the molecular control of DV patterning is conserved inside an insect order, the emergent model hemiptera species Rhodnius prolixus was studied...

The nitrophorins (NPs) comprise an unusual group of heme proteins with stable ferric heme iron nitric oxide (Fe-NO) complexes. They are found in the salivary glands of the blood-sucking kissing bug Rhodnius prolixus, which uses the NPs to transport the highly reactive signaling molecule NO. Nuclear resonance vibrational spectroscopy (NRVS) of both isoform NP2 and a mutant NP2(Leu132Val) show, after addition of NO, a strong structured vibrational band at around 600 cm-1 , which is due to modes with significant Fe-NO bending and stretching contribution...

Entomological surveillance is essential for the control of triatomines and the prevention of Trypanosoma cruzi infection in humans and domestic animals. Thus, the objective of this study was to evaluate entomological indicators and triatomine control during the period from 2005 to 2015 in an endemic area in the state of Rio Grande do Norte, Brazil. This observational and retrospective study was developed based on data analysis related to active entomological surveillance activities and chemical control of infested housing units (HU) in the Agreste mesoregion of the state of Rio Grande do Norte, Brazil, in the period between 2005 to 2015...

BACKGROUND: Physical factors can determine the level of triatomine abundance, but do not regulate their population densities, and neither do natural enemies. OBJECTIVES: To identify the processes associated with density-dependent triatomine population regulation. METHODS: We set-up a laboratory experiment with four interconnected boxes; the central box harbored Rhodnius prolixus bugs and one hamster. Stage 5 and adult densities of 10, 20, 30, 40, and 60 bugs per hamster, were replicated four times (except the density of 60 bugs)...

The high reproductive rates of insects contribute significantly to their ability to act as vectors of a variety of vector-borne diseases. Therefore, it is strategically critical to find molecular targets with biotechnological potential through the functional study of genes essential for insect reproduction. The ubiquitin-proteasome system is a vital degradative pathway that contributes to the maintenance of regular eukaryotic cell proteostasis. This mechanism involves the action of enzymes to covalently link ubiquitin to proteins that are meant to be delivered to the 26S proteasome and broken down...

Chagas disease (CD) is a neglected illness affecting approximately seven million individuals, with vector transmission occurring via triatomine bugs. The Rhodniini tribe comprises 24 species, grouped into the Rhodnius and Psammolestes genera. Given the importance of accurately identifying CD vectors, the taxonomy of Psammolestes spp. was revisited using morphological and morphometric data. Specimens of P. tertius , P. coreodes , and P. arthuri were collected, and the morphological characteristics of the head, thorax, abdomen, and eggs were analyzed...

ATP synthase plays an essential role in mitochondrial metabolism, being responsible for the production of ATP in oxidative phosphorylation. However, recent results have shown that it may also be present in the cell membrane, involved in lipophorin binding to its receptors. Here, we used a functional genetics approach to investigate the roles of ATP synthase in lipid metabolism in the kissing bug Rhodnius prolixus. The genome of R. prolixus encodes five nucleotide-binding domain genes of the ATP synthase alpha and beta family, including the alpha and beta subunits of ATP synthase (RpATPSynA and RpATPSynB), and the catalytic and non-catalytic subunits of the vacuolar ATPase (RpVha68 and RpVha55)...

Rhodnius neglectus is a wild triatomine, vector of the protozoan Trypanosoma cruzi, which causes Chagas' disease, and feeds on the blood of small mammals, being essential for its growth and reproduction. Accessory glands of the female reproductive tract are important in insect reproduction, but their anatomy and histology in R. neglectus are poorly studied. The aim of this work was to describe the histology and histochemistry of the accessory gland of the female reproductive tract of R. neglectus. The reproductive tract of five females of R...