scholarly journals 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

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.

scholarly journals “Urate and NOX5 Control Blood Digestion in the Hematophagous Insect Rhodnius prolixus”

2021 ◽  
Vol 12 ◽  
Author(s):  
Ana Caroline P. Gandara ◽  
Felipe A. Dias ◽  
Paula C. de Lemos ◽  
Renata Stiebler ◽  
Ana Cristina S. Bombaça ◽  
...  
Keyword(s):  
Blood Meal ◽  
Egg Production ◽  
Redox Regulation ◽  
Critical Role ◽  
Rhodnius Prolixus ◽  
Nitrogen Excretion ◽  
Digestive Physiology ◽  
Signaling Crosstalk ◽  
Blood Digestion ◽  
Blood Sucking

Low levels of reactive oxygen species (ROS) are now recognized as essential players in cell signaling. Here, we studied the role of two conserved enzymes involved in redox regulation that play a critical role in the control of ROS in the digestive physiology of a blood-sucking insect, the kissing bugRhodnius prolixus. RNAi-mediated silencing ofRpNOX5andRpXDHinduced early mortality in adult females after a blood meal. Recently, a role forRpNOX5in gut motility was reported, and here, we show that midgut peristalsis is also under the control ofRpXDH. Together with impaired peristalsis, silencing either genes impaired egg production and hemoglobin digestion, and decreased hemolymph urate titers. Ultrastructurally, the silencing ofRpNOX5orRpXDHaffected midgut cells, changing the cells of blood-fed insects to a phenotype resembling the cells of unfed insects, suggesting that these genes work together in the control of blood digestion. Injection of either allopurinol (an XDH inhibitor) or uricase recapitulated the gene silencing effects, suggesting that urate itself is involved in the control of blood digestion. The silencing of each of these genes influenced the expression of the other gene in a complex way both in the unfed state and after a blood meal, revealing signaling crosstalk between them that influences redox metabolism and nitrogen excretion and plays a central role in the control of digestive physiology.

Antennal pathways in the central nervous system of a blood-sucking bug, Rhodnius prolixus

2009 ◽  
Vol 38 (2) ◽  
pp. 101-110 ◽  
Author(s):  
Romina B. Barrozo ◽  
Louise Couton ◽  
Claudio R. Lazzari ◽  
Teresita C. Insausti ◽  
Sebastian A. Minoli ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Rhodnius Prolixus ◽  
Blood Sucking ◽  
The Central Nervous System

scholarly journals Central nervous system involvement in Chagas' disease: an updating

1993 ◽  
Vol 35 (2) ◽  
pp. 111-116 ◽  
Author(s):  
José Eymard Homem Pittella
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Chagas Disease ◽  
Acute Phase ◽  
Central Nervous System Involvement ◽  
Cns Infection ◽  
Cns Involvement ◽  
Anatomical Basis ◽  
Immunosuppressed Patients ◽  
Acute Form

A review was made of the available literature on central nervous system (CNS) involvement in Chagas' disease. Thirty-one works concerning the acute nervous form and 17 others dealing with the chronic nervous form, all presenting neuropathologic studies, were critically analysed. Based on this analysis, an attempt was made to establish the possible natural history of CNS involvement in Chagas' disease. Among others, the following facts stand out: 1) the initial, acute phase of Trypanosoma cruzi infection is usually asymptomatic and subclinical; 2) only a small percentage of cases develop encephalitis in the acute phase of Chagas' disease; 3) the symptomatic acute forms accompanied by chagasic encephalitis are grave, with death ensuing in virtually all cases as a result of the brain lesions per se or of acute chagasic myocarditis, this being usually intense and always present; 4) individuals with the asymptomatic acute form and with the mild symptomatic acute form probably have no CNS infection or, in some cases, they may have discrete encephalitis in sparse foci. In the latter case, regression of the lesions may be total, or residual inflammatory nodules of relative insignificance may persist. Thus, no anatomical basis exists that might characterize the existence of a chronic nervous form of Chagas' disease; 5) reactivation of the CNS infection in the chronic form of Chagas' disease is uncommon and occurs only in immunosuppressed patients.

Motor responses of Rhodnius prolixus Stål (Hem., Reduviidae) to volatile drugs

1971 ◽  
Vol 61 (2) ◽  
pp. 309-313 ◽  
Author(s):  
Ian McLure
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Carbon Tetrachloride ◽  
Chloral Hydrate ◽  
Rhodnius Prolixus ◽  
The Other ◽  
Motor Responses ◽  
Normal Feeding ◽  
Insect Central Nervous System ◽  
Differential Action

Fifth-instar nymphs of Rhodnius prolixus Stålwere exposed to the vapours of 11 volatile drugs: acetone, bromobenzene, bromoform, carbon tetrachloride, chloral hydrate, chloroform, dioxane, ethanol, ethyl ether, isopropanol and paraldehyde. Bromobenzene, bromoform, carbon tetrachloride, chloroform and ether induced reversible anaesthesia. For each of these five, the insects exhibited a different andspecific pattern of motor responses before becoming totally immobile; these responses are described. The responses to carbon tetrachloride are similar to the normal feeding responses of this insect. The other six drugs did not induce anaesthesia, but instead, a commonand stereotyped pattern of cleaning responses, suggesting irritation of the sensory organs. It is proposed that the agent-specific responses to the anaesthesiainducing drugs are due to their differential action upon specific portions of the insect central nervous system.

Haemolymph Proteins and Yolk Formation in Rhodnius Prolixus Stål

1965 ◽  
Vol 43 (3) ◽  
pp. 425-431
Author(s):  
G. C. COLES
Keyword(s):  
Cellulose Acetate ◽  
Total Protein ◽  
Egg Production ◽  
Fat Body ◽  
Rhodnius Prolixus ◽  
Hormonal Control ◽  
Protein Fractions ◽  
Yolk Formation ◽  
Specific Proteins

1. There are two adult-specific proteins in the haemolymph of Rhodnius. They appear to be formed in the fat body. 2. The two proteins are absorbed by the oocytes and form the bulk of the soluble egg proteins. 3. The changes in the concentration of total protein in the haemolymph and of four protein fractions, as separated on cellulose acetate, do not reflect egg production. This may be a consequence of the hormonal control of reproduction.

scholarly journals The remarkable pioneering contribution of Gaspar Vianna to the study of the neuropathology of Chagas disease

2018 ◽  
Vol 76 (12) ◽  
pp. 853-856
Author(s):  
José Eymard Homem Pittella
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Life Cycle ◽  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Acute Phase ◽  
Central Nervous System Involvement ◽  
System Involvement

ABSTRACT Gaspar Vianna is considered one of the great names in Medicine and Science in Brazil. Yet, little prominence has been given to his studies in Neuropathology. He was the first to describe, in 1911, the histopathology and pathogenesis of chagasic encephalitis in the acute phase of Chagas disease, as well as the intracellular life cycle of Trypanosoma cruzi. Over 100 years have elapsed and Gaspar Vianna's pioneering study remains an example of a meticulous and still up-to-date description of central nervous system involvement in the acute phase of Chagas disease.

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

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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