Genome of Rhodnius prolixus, an insect vector of Chagas disease, reveals unique adaptations to hematophagy and parasite infection

Rhodnius prolixus not only has served as a model organism for the study of insect physiology, but also is a major vector of Chagas disease, an illness that affects approximately seven million people worldwide. We sequenced the genome of R. prolixus, generated assembled sequences covering 95% of the genome (∼702 Mb), including 15,456 putative protein-coding genes, and completed comprehensive genomic analyses of this obligate blood-feeding insect. Although immune-deficiency (IMD)-mediated immune responses were observed, R. prolixus putatively lacks key components of the IMD pathway, suggesting a reorganization of the canonical immune signaling network. Although both Toll and IMD effectors controlled intestinal microbiota, neither affected Trypanosoma cruzi, the causal agent of Chagas disease, implying the existence of evasion or tolerance mechanisms. R. prolixus has experienced an extensive loss of selenoprotein genes, with its repertoire reduced to only two proteins, one of which is a selenocysteine-based glutathione peroxidase, the first found in insects. The genome contained actively transcribed, horizontally transferred genes from Wolbachia sp., which showed evidence of codon use evolution toward the insect use pattern. Comparative protein analyses revealed many lineage-specific expansions and putative gene absences in R. prolixus, including tandem expansions of genes related to chemoreception, feeding, and digestion that possibly contributed to the evolution of a blood-feeding lifestyle. The genome assembly and these associated analyses provide critical information on the physiology and evolution of this important vector species and should be instrumental for the development of innovative disease control methods.

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Pigmentation loci as markers for genome editing in the Chagas disease vector Rhodnius prolixus

10.1101/2020.04.29.067934 ◽

2020 ◽

Author(s):

M. Berni ◽

D. Bressan ◽

Y. Simão ◽

A. Julio ◽

P. L. Oliveira ◽

...

Keyword(s):

Genome Editing ◽

Chagas Disease ◽

Rhodnius Prolixus ◽

Disease Spread ◽

Great Promise ◽

Insect Vector ◽

Alternative Strategies ◽

Primary Model ◽

Genes Encoding ◽

Eye Pigmentation

AbstractThe kissing bug Rhodnius prolixus is a major vector for Chagas disease in the Americas, and also considered as the primary model for functional studies. Prospective transgenic approaches and genome editing strategies hold great promise for controlling insect populations as well as disease propagation. In this context, identifying visible genetic markers for transgenic methodologies is of paramount importance to advance the field. Here we have identified and analyzed the function of putative cuticle and eye color genes by investigating the effect of gene knockdown on fertility, viability, and the generation of visible phenotypes. Synthesis of the dark, yellow and tan pigments present in the cuticle of most insects depends on the function of key genes encoding enzymes in the tyrosine pathway. Knockdown of the R. prolixus yellow and aaNAT/pro orthologs produces striking alterations in cuticle color. Surprisingly, knockdown of ebony does not generate visible phenotypes. Since loss of ebony function results in a dark cuticle in several insect orders, we conclude that R. prolixus evolved alternative strategies for cuticle coloration, possibly including the loss of a pigmentation function for an entire branch of the tyrosine pathway. Knockdown of the scarlet and brown genes - encoding ABC transporters - alters cuticle and eye pigmentation, implying that the transport of pigment into proper organelles is an important process both for cuticle and eye coloration in this species. Therefore, this analysis identifies for the first time potential visible markers for transgenesis in a hemipteran vector for a debilitating human disease.Author SummaryThe hemipteran Rhodnius prolixus - also known as a kissing bug - is a main vector transmitting the parasite Trypanosoma cruzi, the causative agent of Chagas disease, a debilitating infection estimated to affect more than 6 million people in Central and South America. In order to limit disease spread, an important measure is insect vector control. However, kissing bugs - like other insects - develop resistance to insecticides. Alternative strategies based on transgenesis and the recently developed CRISPR- based genome edition hold great promise to control vector population or generate parasite-resistant insects. For these approaches to be feasible in R. prolixus, it is critical to identify visible phenotypic markers. Here we identify and describe several genes controlling cuticle and eye pigmentation that are well-suited putative landing sites for transformation strategies. Among these, loss-of-function mutations in the ABC transporter encoding scarlet and the tyrosine pathway enzyme encoding aaNAT/pro generate striking and easily visible phenotypes. Importantly, the knockdown of these genes does not affect insect viability and fertility under laboratory conditions. Our results suggest that R. prolixus has developed alternative strategies for cuticle coloration involving the loss of an entire branch of tanning loci, while the other branch producing cuticle patterns by generating non-pigmented areas has gained critical importance.

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Correction for Mesquita et al., Genome of Rhodnius prolixus, an insect vector of Chagas disease, reveals unique adaptations to hematophagy and parasite infection

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1600205113 ◽

2016 ◽

Vol 113 (10) ◽

pp. E1415-E1416 ◽

Cited By ~ 5

Keyword(s):

Chagas Disease ◽

Rhodnius Prolixus ◽

Parasite Infection ◽

Insect Vector

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Faculty Opinions recommendation of Genome of Rhodnius prolixus, an insect vector of Chagas disease, reveals unique adaptations to hematophagy and parasite infection.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.725980035.793531595 ◽

2017 ◽

Author(s):

Martin Giurfa

Keyword(s):

Chagas Disease ◽

Rhodnius Prolixus ◽

Parasite Infection ◽

Insect Vector

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The neuropeptide RhoprCCHamide2 inhibits serotonin-stimulated transcellular Na+ transport across the anterior midgut of the vector of Chagas disease Rhodnius prolixus

Journal of Experimental Biology ◽

10.1242/jeb.242272 ◽

2021 ◽

Author(s):

Natalia Capriotti ◽

Paula Gioino ◽

Sheila Ons ◽

Juan P. Ianowski

Keyword(s):

Chagas Disease ◽

Short Circuit ◽

Ussing Chamber ◽

Rhodnius Prolixus ◽

Malpighian Tubules ◽

Insect Vector ◽

Na Channels ◽

Atpase Inhibitor ◽

Plasma Fraction ◽

Anterior Midgut

Rhodnius prolixus is a blood-feeding insect vector of Tripanosoma cruzi, a protozoan parasite that causes Chagas' disease. During each blood meal the animals ingest large volumes of blood, that may be up to 12 times the unfed body mass. These blood meals impose a significant osmotic stress for the animals due to the hyposmotic condition of the ingested blood compared to the insect's haemolymph. Thus, the insect undergoes a massive postprandial diuresis that allows for the excretion of the plasma fraction of the blood in less than two hours. Diuresis is performed by the excretory system, consisting of the Malpighian tubules and gut, under the control of diuretic and antidiuretic factors. We investigated the ion transport machinery triggered by stimulation with the diuretic factor serotonin in the anterior midgut (i.e. crop) and the effect of the diuretic modulator RhoprCCHamide2. Ussing chamber assays revealed that serotonin-stimulated increase in transepithelial short circuit current (Isc) was more sensitive to the blockage with amiloride than EIPA, suggesting the involvement of Na+ channels. Incubation in Na+-free, but not Cl−-free saline, blocked the effect of serotonin on Isc. Moreover, treatment with NKCC and NCC blockers had no effect on fluid secretion but was blocked by amiloride. Blockage of Na+/K+-ATPase with ouabain inhibit Isc but the H+-ATPase inhibitor bafilomycin had no effect. The neuropeptide RhoprCCHamide2 diminished serotonin-stimulated Isc across the crop. The results suggest that Na+ undergoes active transport via an apical amiloride-sensitive Na+ channels and a basolateral ouabain-sensitive Na+/K+-ATPase while Cl− is transported through passive paracellular pathway.

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Early Post-Prandial Regulation of Protein Expression in the Midgut of Chagas Disease Vector Rhodnius prolixus Highlights New Potential Targets for Vector Control Strategy

Microorganisms ◽

10.3390/microorganisms9040804 ◽

2021 ◽

Vol 9 (4) ◽

pp. 804

Author(s):

Radouane Ouali ◽

Larissa Rezende Vieira ◽

Didier Salmon ◽

Sabrina Bousbata

Keyword(s):

Protein Expression ◽

Chagas Disease ◽

Potential Role ◽

Vector Competence ◽

Blood Feeding ◽

Rhodnius Prolixus ◽

Label Free ◽

Proteomics Data ◽

Early Effect ◽

Posterior Midgut

Chagas disease is a vector-borne parasitic disease caused by the flagellated protozoan Trypanosoma cruzi and transmitted to humans by a large group of bloodsucking triatomine bugs. Triatomine insects, such as Rhodnius prolixus, ingest a huge amount of blood in a single meal. Their midgut represents an important interface for triatomine–trypanosome interactions. Furthermore, the development of parasites and their vectorial transmission are closely linked to the blood feeding and digestion; thus, an understanding of their physiology is essential for the development of new strategies to control triatomines. In this study, we used label-free quantitative proteomics to identify and analyze the early effect of blood feeding on protein expression in the midgut of Rhodnius prolixus. We both identified and quantified 124 proteins in the anterior midgut (AM) and 40 in the posterior midgut (PM), which vary significantly 6 h after feeding. The detailed analysis of these proteins revealed their predominant involvement in the primary function of hematophagy, including proteases, proteases inhibitors, amino acids metabolism, primary metabolites processing, and protein folding. Interestingly, our proteomics data show a potential role of the AM in protein digestion. Moreover, proteins related to detoxification processes and innate immunity, which are largely accepted to be triggered by blood ingestion, were mildly modulated. Surprisingly, one third of blood-regulated proteins in the AM have unknown function. This work contributes to the improvement of knowledge on the digestive physiology of triatomines in the early hours post-feeding. It provides key information for selecting new putative targets for the development of triatomine control tools and their potential role in the vector competence, which could be applied to other vector species.

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

Parasitology ◽

10.1017/s0031182015001857 ◽

2016 ◽

Vol 143 (4) ◽

pp. 434-443 ◽

Cited By ~ 29

Author(s):

ROBERTA CARVALHO FERREIRA ◽

RAFAEL LUIS KESSLER ◽

MARCELO GUSTAVO LORENZO ◽

RAFAELA MAGALHÃES MACEDO PAIM ◽

LUCIANA DE LIMA FERREIRA ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Population Size ◽

Chagas Disease ◽

Intestinal Tract ◽

Parasite Load ◽

Rhodnius Prolixus ◽

Insect Vector ◽

Posterior Midgut ◽

Development And Differentiation ◽

Anterior Midgut

SUMMARYTrypanosoma 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. Approximately 20% of the ingested parasites was found in the insect anterior midgut (AM) 3 h after feeding. Interestingly, a significant reduction (80%) in the numbers of trypomastigotes was observed after 24 h of infection suggesting that parasites were killed in the AM. Moreover, few parasites were found in that intestinal portion after 96 h of infection. The evaluation of the numbers of parasites in the posterior midgut (PM) at the same periods showed a reduced parasite load, indicating that parasites were not moving from the AM. Additionally, incubation of blood trypomastigotes with extracts from R. prolixus AMs revealed that components of this tissue could induce significant death of T. cruzi. Finally, we observed that differentiation from trypomastigotes to epimastigotes is not completed in the AM; instead we suggest that trypomastigotes change to intermediary forms before their migration to the PM, where differentiation to epimastigotes takes place. The present work clarifies controversial points concerning T. cruzi development in insect vector, showing that parasite suffers a drastic decrease in population size before epimastigonesis accomplishment in PM.

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What happens after a blood meal? A transcriptome analysis of the main tissues involved in egg production in Rhodnius prolixus, an insect vector of Chagas disease

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0008516 ◽

2020 ◽

Vol 14 (10) ◽

pp. e0008516

Author(s):

Jimena Leyria ◽

Ian Orchard ◽

Angela B. Lange

Keyword(s):

Chagas Disease ◽

Transcriptome Analysis ◽

Blood Meal ◽

Egg Production ◽

Rhodnius Prolixus ◽

Insect Vector

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What happens after a blood meal? A transcriptome response from the main tissues involved in egg production in Rhodnius prolixus, an insect vector of Chagas disease

10.1101/2020.06.26.173195 ◽

2020 ◽

Author(s):

Jimena Leyria ◽

Ian Orchard ◽

Angela B. Lange

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Chagas Disease ◽

Blood Meal ◽

Egg Production ◽

Fat Body ◽

Rhodnius Prolixus ◽

Insect Vector ◽

Blood Sucking ◽

Epidemiological Impact

AbstractThe blood-sucking hemipteran Rhodnius prolixus is a vector of Chagas disease, one of the most neglected tropical diseases affecting several million people, mostly in Latin America. The blood meal is an event with a high epidemiological impact since in adult mated females it initiates the production of hundreds of eggs. By means of RNA-Sequencing (RNA-Seq) we have examined how a blood meal influences mRNA expression in the central nervous system (CNS), fat body and ovaries in order to promote egg production, focusing on tissue-specific responses under controlled nutritional conditions. We illustrate the cross talk between reproduction and a) lipids, proteins and trehalose metabolism, b) neuropeptide and neurohormonal signaling, and c) the immune system. Overall, our molecular evaluation confirms and supports previous studies and provides an invaluable molecular resource for future investigations on different tissues involved in successful reproductive events. Analyses like this can be used to increase the chances of developing novel strategies of vector population control by translational research, with less impact on the environment and more specificity for a particular organism.Author summaryThe blood-sucking hemipteran Rhodnius prolixus is one of the main vectors of Chagas disease. The blood meal is an event with a high epidemiological impact since in adult mated females, blood-gorging leads to the production of hundreds of eggs. This work describes an in-depth central nervous system (CNS), ovary and fat body transcriptome analysis, focusing on transcripts related to blood intake which may be relevant in promoting egg production. To date, the principle focus in Chagas disease prevention is on the elimination of triatomine vectors and their progeny. This work will serve as a starting point for initiating novel investigations on targets identified with a potential for use in vector control; for example using specific genes to generated symbiont-mediated RNAi, a powerful technology which provides a novel means in biocontrol against tropical disease vectors.

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Metabolic reprogramming during the Trypanosoma brucei life cycle

F1000Research ◽

10.12688/f1000research.10342.2 ◽

2017 ◽

Vol 6 ◽

pp. 683 ◽

Cited By ~ 31

Author(s):

Terry K. Smith ◽

Frédéric Bringaud ◽

Derek P. Nolan ◽

Luisa M. Figueiredo

Keyword(s):

Life Cycle ◽

Trypanosoma Brucei ◽

Model Organism ◽

Protozoan Parasite ◽

Tsetse Fly ◽

Metabolic Reprogramming ◽

Mammalian Host ◽

Insect Vector ◽

Environmental Signals ◽

Cellular Metabolic Activity

Cellular metabolic activity is a highly complex, dynamic, regulated process that is influenced by numerous factors, including extracellular environmental signals, nutrient availability and the physiological and developmental status of the cell. The causative agent of sleeping sickness, Trypanosoma brucei, is an exclusively extracellular protozoan parasite that encounters very different extracellular environments during its life cycle within the mammalian host and tsetse fly insect vector. In order to meet these challenges, there are significant alterations in the major energetic and metabolic pathways of these highly adaptable parasites. This review highlights some of these metabolic changes in this early divergent eukaryotic model organism.

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