RNA interference of the clock gene period disrupts circadian rhythms in the expression of genes related to insecticide resistance in the chagas disease vector Triatoma infestans (Hemiptera: Reduviidae).

In Triatoma infestans it was observed pyrethroid resistance attributed in part to an elevated oxidative metabolism mediated by cytochromes P450. The nicotinamide adenine dinucleotide phosphate (NADPH) cytochrome P450 reductase (CPR) plays a crucial role in catalysing the electron transfer from NADPH to all cytochrome P450s. The daily variations in the expression of CPR gene and a P450 gene (CYP4EM7), both associated with insecticide resistance, suggested that their expressions would be under the endogenous clock control.

RNA interference of NADPHcytochrome P450 increased deltamethrin susceptibility in a resistant strain of the Chagas disease vector Triatoma infestans.

The enzyme NADPH-cytochrome P450 reductase (CPR) plays a central role in cytochromes P450 activity. Gene expression analysis of cytochromes P450 and CPR in deltamethrin-resistant and susceptible populations revealed that P450s genes are involved in the development of insecticide resistance in Triatoma infestans. To clarify the role of cytochromes P450 in insecticide resistance, it was proposed to investigate the effect of CPR gene silencing by RNA interference (RNAi) in a pyrethroid resistant population of T.

Clock Gene in the Chagas Disease Vector (Hemiptera: Reduviidae).

To contribute to a better understanding of the molecular basis of the circadian biological rhythms in Chagas disease vectors, in this work we identified functional domains in the sequences of the clock protein TIMELESS (TIM) in and analyzed the expression of the () gene at the mRNA level in . The gene expression in nervous tissue of adult revealed clear oscillations in the abundance of the transcript in both sexes in the group maintained under photoperiod with a daily canonical rhythm, showing a significant increase in expression at sunset. As expected, in the group maintained in constant light, no daily increase was detected in the transcript level.

Daily Variations in the Expression of Genes Related to Insecticide Resistance in the Chagas Disease Vector (Hemiptera: Reduviidae).

Pyrethroid resistance has been detected in , which in part has been attributed to increased oxidative metabolism of the insecticide by cytochrome P450s. Nicotinamide adenine dinucleotide phosphate (NADPH) cytochrome P450 reductase (CPR) catalyzes electron transfer from NADPH to all known cytochrome P450s. In this study, the expression of the gene at transcriptional level was determined in different tissues and two life stages.

cDNA Isolation and Expression of Nicotinamide Adenine Dinucleotide Phosphate-Dependent Cytochrome P450 Reductase Gene in the Chagas Disease Vector .

Pyrethroid resistance has been detected in (Hemiptera: Reduviidae), which was atributed to target site insensitivity and increased oxidative metabolism of the insecticide by cytochrome P450s. Nicotinamide adenine dinucleotide phosphate (NADPH) cytochrome P450 reductase (CPR) plays an essential role in transferring electrons from NADPH to the P450-substrate complex. In this study, the full length cDNA of was isolated and gene expression was determined by quantitative polymerase chain reaction.

Clock Gene in the Chagas Disease Vector (Hemiptera: Reduviidae).

To contribute to a better understanding of the molecular bases of the circadian biological rhythms in Chagas disease vectors, in this work we identified functional domains in the sequences of the clock protein PERIOD (PER) in and and analyzed the expression of the PER gene at mRNA level in . The PER protein sequences comparison among these species and those from other insects revealed that the most similar regions are the PAS domains and the most variable is the COOH-terminal. On the other hand, the gene expression in nervous tissue of adult varies with a daily canonical rhythm in groups of individuals maintained under photoperiod (light/dark, LD) and constant dark (DD), showing a significant peak of expression at sunset.

Involvement of the brain renin-angiotensin system (RAS) in the neuroadaptive responses induced by amphetamine in a two-injection protocol.

A single or repeated exposure to psychostimulants induces long-lasting neuroadaptative changes. Different neurotransmitter systems are involved in these responses including the neuropeptide angiotensin II. Our study tested the hypothesis that the neuroadaptative changes induced by amphetamine produce alterations in brain RAS components that are involved in the expression of the locomotor sensitization to the psychostimulant drug.

Daily variations in the glycerol-3-phosphate dehydrogenase isoforms expression in Triatoma infestans flight muscles.

Triatoma infestans, the main vector of Chagas disease, is a blood-sucking insect. Flight dispersal of adults is the most important mechanism for reinfestation of houses after insecticide spraying. Flight muscles have two glycerol-3-phosphate dehydrogenase (GPDH) isoforms: GPDH-1 is involved in flight metabolism and GPDH-2 provides lipid precursors.

Molecular Population Genetics and Evolution of the Chagas' Disease Vector Triatoma infestans (Hemiptera: Reduviidae).

Triatoma infestans (Klug) is the main vector of Chagas' disease in the Southern Cone of Latin America between the latitudes 10° S and 46° S. The long-term effectiveness of the control campaigns is greatly dependent upon the vector population structure. Mitochondrial DNA (mtDNA) genes have been used in a number of T.

Differential expression of glycerol-3-phosphate dehydrogenase isoforms in flight muscles of the Chagas disease vector Triatoma infestans (Hemiptera, Reduviidae).

Flight muscles of Triatoma infestans have two glycerol-3-phosphate dehydrogenase (GPDH) isoforms: GPDH-1 is involved in flight metabolism and GPDH-2 provides lipid precursors. Total GPDH activity was greater in the natural population and almost only due to GPDH-1. Different expression and activity observed between GPDH isoforms in the natural population and the first laboratory generation was not detected in the second laboratory generation.

Functional and proteomic analysis of submandibular saliva in rats exposed to chronic stress by immobilization or constant light.

Objective: In this study, we have evaluated the effects of stress on functional and proteomic changes in submandibular saliva of rats.

Design: Male adult rats were divided in three groups: IMO (2 h/day of immobilization for 7 days), LL (constant light during 20 days), C (unstressed controls submitted to 14 h light-10h dark cycle). Body weight, food intake and the dry weight of submandibular gland were recorded.

Gene discovery in Triatoma infestans.

Background: Triatoma infestans is the most relevant vector of Chagas disease in the southern cone of South America. Since its genome has not yet been studied, sequencing of Expressed Sequence Tags (ESTs) is one of the most powerful tools for efficiently identifying large numbers of expressed genes in this insect vector.

Results: In this work, we generated 826 ESTs, resulting in an increase of 47% in the number of ESTs available for T.