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a caged cyanide.a photoactivatable caged cyanide, 1-(2-nitrophenyl)ethyl (npe) cyanide, was synthesized, which upon irradiation in the near uv releases cyanide. it is demonstrated that the compound can be used to induce formation of the fe(iii)-cn(-) complex in the heme protein nitrophorin 4 from rhodnius prolixus.201222406687
identification of the native n-terminus of the membrane attaching ferriheme protein nitrophorin 7 from rhodnius prolixus.all species of the genus rhodnius have a characteristic red coloration in their salivary glands due to the presence of heme proteins. some of these secreted proteins, known as nitrophorins (nps), are responsible for many of the antihemostatic activities of rhodnius saliva such as anticoagulant and antihistamine. several nps have been described (np1-4 and np7), where np7 is the only one with affinity to phospholipid membranes. computational prediction suggested that np7 also has an extended n-ter ...201222349021
nuclear inelastic scattering and mössbauer spectroscopy as local probes for ligand binding modes and electronic properties in proteins: vibrational behavior of a ferriheme center inside a β-barrel protein.in this work, we present a study of the influence of the protein matrix on its ability to tune the binding of small ligands such as no, cyanide (cn(-)), and histamine to the ferric heme iron center in the no-storage and -transport protein nitrophorin 2 (np2) from the salivary glands of the blood-sucking insect rhodnius prolixus. conventional mössbauer spectroscopy shows a diamagnetic ground state of the np2-no complex and type i and ii electronic ground states of the np2-cn(-) and np2-histamine ...201222295945
crystallization and preliminary x-ray crystallographic analysis of the membrane-binding haemprotein nitrophorin 7 from rhodnius prolixus.nitrophorins (nitric oxide transport proteins) are haemproteins originating from the blood-feeding insect rhodnius prolixus. they consist of an eight-stranded β-barrel, which classifies them into the lipocalin family. nitrophorin 7 (np7) and the e27v mutant protein np7(e27v) were crystallized at 277 k using the vapour-diffusion method with peg as the precipitating agent. data sets for wild-type np7 and np7(e27v) were collected to 1.80 å resolution from single crystals at 100 k using synchrotron ...201222232167
recent experiments towards a model for fluid secretion in rhodnius upper malpighian tubules (umt).three different methods have been used to improve a model for fluid secretion in upper malpighian tubules (umt) of the blood sucking insect rhodnius prolixus. (i) in the first, umt double perfusions in 5th instar rhodnius were used to measure their fluid secretion rate. they were stimulated to secrete with 5-ht. double perfusions allowed access separately to the basolateral and the apical cell membranes with pharmacological agents known to block different ion transport functions, namely atpases, ...201222206885
natriuresis and diuretic hormone synergism in r. prolixus upper malpighian tubules is inhibited by the anti-diuretic hormone, rhoprcapa-α2.insects contain an array of hormones that coordinate the actions of the excretory system to achieve osmotic and ionic balance. in the hematophagous insect, rhodnius prolixus, two diuretic hormones have been identified, serotonin (5ht) and a corticotropin releasing factor-related peptide (rhoprdh), and both lead to an increase in fluid secretion by malpighian tubules (mts). however, only 5ht activates reabsorption by the lower mts to recover k(+) and cl(-). an anti-diuretic hormone (rhoprcapa-α2) ...201222154955
rhythmic release of prothoracicotropic hormone from the brain of an adult insect during egg development.prothoracicotropic hormone (ptth) is a brain neurohormone that has been studied for over 80 years. the only known target of ptth is the prothoracic glands (pgs) of larvae, which synthesize the insect molting hormones (ecdysteroids) and a massive literature exists on this axis. the pgs degenerate around the time of adult emergence, yet presence of ptth has been reported in the brains of several adult insects. using an in vitro bioassay system, we confirm that ptth is present in the adult female b ...201222079105
cloning of the cdna, localization, and physiological effects of fglamide-related allatostatins in the blood-gorging bug, rhodnius prolixus.allatostatins (asts) are insect neuropeptides that were first identified as inhibitors of juvenile hormone biosynthesis by the corpora allata. there are three families of asts in insects, defined by their c-terminus conserved regions, one of which is fglamide. here we determine, for the first time in a hemipteran, the complete 1013 bp cdna sequence encoding the rhodnius prolixus fgla/asts (rhopr-fgla/asts), and confirm the transcript size using northern blot. phylogenetic analysis suggests that ...201222061445
the gap gene giant of rhodnius prolixus is maternally expressed and required for proper head and abdomen formation.the segmentation process in insects depends on a hierarchical cascade of gene activity. the first effectors downstream of the maternal activation are the gap genes, which divide the embryo in broad fields. we discovered a sequence corresponding to the leucine-zipper domain of the orthologue of the gene giant (rp-gt) in traces from the genome of rhodnius prolixus, a hemipteran with intermediate germ-band development. we cloned the rp-gt gene from a normalized cdna library and characterized its ex ...201221763688
substrate texture properties induce triatomine probing on bitten warm surfaces.in this work we initially evaluated whether the biting process of rhodnius prolixus relies on the detection of mechanical properties of the substrate. a linear thermal source was used to simulate the presence of a blood vessel under the skin of a host. this apparatus consisted of an aluminium plate and a nickel-chrome wire, both thermostatized and presented at 33 and 36°c, respectively. to evaluate whether mechanical properties of the substrate affect the biting behaviour of bugs, this apparatus ...201121682881
nitrophorins: nitrite disproportionation reaction and other novel functionalities of insect heme-based nitric oxide transport proteins.nitrophorins (nps) comprise a unique class of heme proteins used by the blood-sucking insect rhodnius prolixus to deliver the signaling gas molecule no into the blood vessel of a host during feeding. upon no release, histamine can be scavenged by coordination to the heme iron. although the protein is of similar size as the mammalian globin monomers and shares the same cofactor and proximal histidine coordination, nitrophorin structure, in contrast, is almost entirely composed of a β-barrel. comp ...201121491557
the activity of platelet activating factor-acetyl hydrolase (paf-ah) in the salivary glands of rhodnius prolixus.in this work, we investigated the activity of the platelet activating factor acetyl hydrolase (paf-ah) in the salivary gland homogenates and saliva of rhodnius prolixus. paf-ah activity in the salivary gland homogenates was lower than in the saliva. preliminary characterization of the enzyme demonstrated that it hydrolyzed the substrate 2-thio-paf, was detectable just in 1 pair of salivary gland homogenates in 0.5 ml buffer, and was stable under different conditions. pmsf, tpck, tlck, pepstatin ...201121439293
lipid accumulation and utilization by oocytes and eggs of rhodnius prolixus.insect eggs must contain the necessary nutrients for embryonic growth. in this article, we investigated the accumulation of triacylglycerol (tag) in growing oocytes and its utilization during embryonic development. tag makes up about 60% of the neutral lipids in oocytes and accumulates as oocytes grow, from 2.2 ± 0.1 µg in follicles containing 1.0 mm length oocytes to 10.2 ± 0.8 µg in 2.0 mm length oocytes. lipophorin (lp), the hemolymphatic lipoprotein, radioactively labeled in free fatty acid ...201121308762
identification of the elusive peptidergic diuretic hormone in the blood-feeding bug rhodnius prolixus: a crf-related peptide.probing of a host and ingestion of a blood-meal in a fifth instar rhodnius prolixus results in a cascade of tightly integrated events. the huge blood-meal is pumped into the anterior midgut during feeding, then modified by diuresis and stored until it is digested. while serotonin is known to be a diuretic hormone in r. prolixus, a peptidergic factor(s) was also known to play a role in diuresis. in the present study we employed molecular techniques and mass spectrometry to determine the sequence ...201121228196
identification of kinin-related peptides in the disease vector, rhodnius prolixus.we have used an in silico approach to identify a gene from the blood-gorging vector, rhodnius prolixus, that is predicted to produce an insect kinin prepropeptide. the prepropeptide is 398 amino acids in length and can potentially produce a large number of kinin-related peptides following post-translational processing. a comparison with other insect kinin precursor sequences demonstrates greatest conservation at the c-terminal region of the kinin peptides. multiple peptides predicted from the ki ...201120934474
calreticulin expression levels and endoplasmic reticulum during late oogenesis and early embryogenesis of rhodnius prolixus stahl.this study reports the cloning, expression analysis and localization of calreticulin (crt) in the endoplasmic reticulum (er) during late oogenesis and early embryogenesis of the insect rhodnius prolixus. crt was cloned and sequenced from cdna extracted from unfertilized eggs. real-time pcr showed that crt expression remains at lower levels during late oogenesis when compared to vitellogenic oocytes or day 0 laid fertilized eggs. immunofluorescence microscopy showed that this protein is located i ...201120857219
isolation and characterization of the cdna encoding dh(31) in the kissing bug, rhodnius prolixus.rhodnius prolixus undergoes a period of rapid diuresis after ingesting large blood meals. neurohormones with either diuretic or anti-diuretic activity control diuresis by acting on several tissues including the malpighian tubules. one of the neurohormones that potentially plays a role in diuresis is diuretic hormone 31 (dh(31)) which belongs to the insect calcitonin-like family of diuretic hormones. here we determine the complete cdna sequences of three rhopr-dh(31) splice variants (rhopr-dh(31) ...201120797422
learning the way to blood: first evidence of dual olfactory conditioning in a blood-sucking insect, rhodnius prolixus. ii. aversive learning.after having demonstrated that blood-sucking bugs are able to associate a behaviourally neutral odour (l-lactic acid) with positive reinforcement (i.e. appetitive conditioning) in the first part of this study, we tested whether these insects were also able to associate the same odour with a negative reinforcement (i.e. aversive conditioning). learned aversion to host odours has been repeatedly suggested as a determinant for the distribution of disease vectors among host populations. nevertheless ...201121865516
response to heat in rhodnius prolixus: the role of the thermal background.heat is the principal host-associated cue for the blood-sucking bug rhodnius prolixus. it is both necessary and sufficient to trigger the "proboscis extension response" (per), an essential element of the feeding behaviour of this insect. the aim of this study was to determine whether the temperature of an object itself or the thermal contrast between the object and the environmental background is responsible for triggering the per. thermal stimuli at 25-50°c were presented in thermal environment ...201121806990
adaptation of the repellency response to deet in rhodnius prolixus.for many years it has been accepted that deet interferes with the detection of odours from the host instead of having a repellent effect. however, recent work showed that deet acts as an odorant molecule and elicits a behavioural response in the absence of other stimuli. therefore, deet must promote some phenomenon connected with the stimuli-sensory system interaction, such as a sensory adaptation, where the sensory system regulates its sensitivity to different stimuli intensities during continu ...201121801727
[new trap for the capture of triatomines in wild and peridomestic habitats].wild triatomines have become increasingly important in the transmission of chagas disease because of their frequent house entry behavior. knowledge of their biology is limited, and few tools are available for their collection. these needs led to the design of a new trap for live triatomines.201122159544
crustacean cardioactive peptide in the chagas' disease vector, rhodnius prolixus: presence, distribution and physiological effects.crustacean cardioactive peptide (ccap), a cyclic nonapeptide (pfcnaftgcamide), has multifunctional roles in insects including stimulating visceral and cardiac muscle contraction, and regulating ecdysis. previously, we have sequenced the cdna for ccap from rhodnius prolixus central nervous system (cns) and shown expression of the ccap transcript in neurons of the cns. in the present study, we have biochemically identified and sequenced ccap from 5th instar r. prolixus cns using matrix-assisted la ...201121875591
learning the way to blood: first evidence of dual olfactory conditioning in a blood-sucking insect, rhodnius prolixus. i. appetitive learning.it has been largely assumed that the individual experience of insects that are disease vectors might not only contribute to animal fitness, but also have an important influence on parasite transmission. nevertheless, despite the invested efforts in testing the capacity to learn and remember information in blood-sucking insects, only little conclusive information has been obtained to date. adapting a classical conditioning approach to our haematophagous model, we trained larvae of rhodnius prolix ...201121865515
functional proteomics of neuropeptidome dynamics during the feeding process of rhodnius prolixus.in hematophagous insects, blood intake triggers a prompt response mediated by neuropeptides, which regulates a variety of physiological processes. here we report a quantitative proteomic analysis of the postfeeding response in the central nervous system of rhodnius prolixus, a vector of chagas disease. the concentration of neuropeptides nvp-like, itg-like, kinin-precursor peptide, and neuropeptide-like precursor 1 (nplp1) significantly changes in response to blood intake. we also performed a neu ...201121699238
infestation by triatomine bugs in indigenous communities of valledupar, colombia.to calculate triatomine infestation indices in indigenous communities in colombia.201121670864
isolation, cloning and expression of the crustacean cardioactive peptide gene in the chagas' disease vector, rhodnius prolixus.the blood-gorging bug, rhodnius prolixus, is a major vector of chagas' disease in central and south america. we have cloned and characterized the crustacean cardioactive peptide (ccap) gene in r. prolixus. the rhoprccap gene contains five exons and four introns, and encodes a 129 amino acid prepropeptide, which following post-translation processing, produces ccap. the predicted rhoprccap amino acid sequence is identical to ccap of crustaceans and other insects, i.e. it is highly conserved. rhopr ...201120624439
[rhodnius prolixus in nicaragua: geographical distribution, control, and surveillance, 1998-2009].present an overview of the control of rhodnius prolixus, the principal vector in the transmission of chagas' disease in central america, during the period 1998-2009 in nicaragua. describe the vector control carried out and the geographical distribution of the infested localities.201122262270
[new aspects of the xenodiagnostic method using rhodnius prolixus]. 201114056690
Looking for reference genes for real-time quantitative PCR experiments in Rhodnius prolixus (Hemiptera: Reduviidae).Quantitative real-time PCR (qPCR) has become one of the most used techniques to measure gene expression. However, normalization of gene expression data against reference genes is essential, although these are usually used without any kind of validation. The expression of seven genes was compared in organs of Rhodnius prolixus under diverse conditions, using published software to test gene expression stability. Rp18S and elongation factor 1 (RpEF -1) were the most reliable genes for normalization ...201121929722
[seroprevalence for trypanosoma cruzi infection and associated factors in an endemic area of venezuela].this study investigated risk factors associated with positive serological status for trypanosoma cruzi antibodies in 26 rural communities including 905 households, 2,156 humans, and 333 dogs in lara state, venezuela. serology was performed with elisa and maba. data were obtained from entomological, demographic, and clinical surveys. risk factors were determined through binary logistic regression. seroprevalence was 7.24% in humans and 6.9% in canines. positive serological status was positively a ...201122031196
vital statistics of triatominae (hemiptera: reduviidae) under laboratory conditions: iii. rhodnius neglectus.five cohorts of 100 eggs of rhodnius neglectus lent 1954 (hemiptera reduviidae) were reared simultaneously in the laboratory under constant conditions (26 +/- 1 degrees c and 60 +/- 10% rh), with mortality and fecundity data recorded weekly. we calculated stage-specific developmental times, age-specific mortality and fecundity, stage-specific and total preadult mortality, and the intrinsic rate of natural increase (r0 = 0.21), the finite population growth rate (h = 1.23), the net reproductive ra ...201121845936
prolixicin: a novel antimicrobial peptide isolated from rhodnius prolixus with differential activity against bacteria and trypanosoma cruzi.we identified and characterized the activity of prolixicin, a novel antimicrobial peptide (amp) isolated from the hemipteran insect, rhodnius prolixus. sequence analysis reveals one region of prolixicin that may be related to the diptericin/attacin family of amps. prolixicin is an 11-kda peptide containing a putative 21 amino acid signal peptide, two putative phosphorylation sites and no glycosylation sites. it is produced by both adult fat body and midgut tissues in response to bacterial infect ...201121906194
involvement of sulfated glycosaminoglycans on the development and attachment of trypanosoma cruzi to the luminal midgut surface in the vector, rhodnius prolixus.summaryin the present study, we investigated the involvement of sulfated glycosaminoglycans in both the in vivo development and adhesion of t. cruzi epimastigotes to the luminal surface of the digestive tract of the insect vector, rhodnius prolixus. pre-incubation of t. cruzi, dm 28c epimastigotes with heparin, chondroitin 4-sulfate, chondroitin 6-sulfate or protamine chloridrate inhibited in vitro attachment of parasites to the insect midgut. enzymatic removal of heparan sulfate moieties by hep ...201121902871
characterization of jbure-iib isoform of canavalia ensiformis (l.) dc urease.ureases, nickel-dependent enzymes that catalyze the hydrolysis of urea into ammonia and bicarbonate, are widespread in plants, bacteria, and fungi. previously, we cloned a cdna encoding a canavalia ensiformis urease isoform named jbure-ii, corresponding to a putative smaller urease protein (78kda) when compared to other plant ureases. aiming to produce the recombinant protein, we obtained jbure-iib, with different 3' and 5' ends, encoding a 90kda urease. three peptides unique to the jbure-ii/-ii ...201121893219
female metasternal gland odours mediate male aggregation in rhodnius prolixus, a triatomid bug.we investigated whether metasternal gland (mg) products mediate male aggregation during mating in rhodnius prolixus (heteroptera: reduviidae) stål, 1859, through selective occlusion of female mgs. pairs of insects presenting intact mgs mated and other males aggregated around them confirming conclusions from previous studies. however, when female mgs were occluded, males did not aggregate. conversely, the occlusion of male mgs did not affect aggregation of males. the present experiments demonstra ...201122077398
genetics and evolution of triatomines: from phylogeny to vector control.triatomines are hemipteran bugs acting as vectors of the protozoan parasite trypanosoma cruzi. this parasite causes chagas disease, one of the major parasitic diseases in the americas. studies of triatomine genetics and evolution have been particularly useful in the design of rational vector control strategies, and are reviewed here. the phylogeography of several triatomine species is now slowly emerging, and the struggle to reconcile the phenotypic, phylogenetic, ecological and epidemiological ...201121897436
influence of the intestinal anticoagulant in the feeding performance of triatomine bugs (hemiptera; reduviidae).triatomines are haematophagous insects in all post-embryonic life stages. they are vectors of trypanosoma cruzi, the causative agent of chagas disease. their vectorial ability is influenced by their feeding performance, which varies greatly amongst species. recent work showed that inhibition of the coagulation process in the anterior midgut (crop) environment considerably influences the blood meal size. in this work, we performed a comparative study of the level of anticoagulant activity in the ...201121447340
mdl28170, a calpain inhibitor, affects trypanosoma cruzi metacyclogenesis, ultrastructure and attachment to rhodnius prolixus midgut.trypanosoma cruzi is the etiological agent of chagas' disease. during the parasite life cycle, many molecules are involved in the differentiation process and infectivity. peptidases are relevant for crucial steps of t. cruzi life cycle; as such, it is conceivable that they may participate in the metacyclogenesis and interaction with the invertebrate host.201121483751
importance and physiological effects of hemolymphagy in triatomines (hemiptera: reduviidae).triatomines are hematophagous insects and the vectors for trypanosoma cruzi in the americas. although their preferred meal is blood from vertebrate hosts, unfed triatomine nymphs are often seen feeding on different arthropod species. triatomine saliva has a wide range of activities that aid the hematophagic process. however, nothing is known about its role during hemolymphagy. in the current study, we reproduced hemolymphagy under laboratory conditions and evaluated the influence of hemolymphagy ...201121485376
microscopic and molecular characterization of ovarian follicle atresia in rhodnius prolixus stahl under immune challenge.in this work we characterized the degenerative process of ovarian follicles of the bug rhodnius prolixus challenged with the non-entomopathogenic fungus aspergillus niger. an injection of a. niger conidia directly into the hemocoel of adult r. prolixus females at the onset of vitellogenesis caused no effect on host lifespan but elicited a net reduction in egg batch size. direct inspection of ovaries from the mycosed insects revealed that fungal challenge led to atresia of the vitellogenic follic ...201121540034
mitochondrial disfunction in trypanosoma cruzi: the role of serratia marcescens prodigiosin in the alternative treatment of chagas disease.abstract: background: chagas disease is a health threat for many people, mostly those living in latin america. one of the most important problems in treatment is the limitation of existing drugs. prodigiosin, produced by serratia marcescens (rhodnius prolixus endosymbiont), belongs to the red-pigmented bacterial prodiginine family, which displays numerous biological activities, including antibacterial, antifungal, antiprotozoal, antimalarial, immunosuppressive, and anticancer properties. here we ...201121548954
modeling horizontal gene transfer (hgt) in the gut of the chagas disease vector rhodnius prolixus.abstract: background: paratransgenesis is an approach to reducing arthropod vector competence using genetically modified symbionts. when applied to control of chagas disease, the symbiont bacterium rhodococcus rhodnii, resident in the gut lumen of the triatomine vector rhodnius prolixus (hemiptera: reduviidae), is transformed to export cecropin a, an insect immune peptide. cecropin a is active against trypanosoma cruzi, the causative agent of chagas disease.while proof of concept has been achiev ...201121569540
nmr studies of nitrophorin distal pocket side chain effects on the heme orientation and seating of np2 as compared to np1.the nitrophorins (np) of the adult blood-sucking insect rhodnius prolixus fall into two pairs based on sequence identity (np1,4 (90%) and np2,3 (79%)), which differ significantly in the size of side chains of residues which contact the heme. these residues include those in the distal pocket of np2 (i120) and np1 (t121) and the "belt" that surrounds the heme of np2 (s40, f42), and np1(a42, l44). to determine the importance of these residues and others conserved or very similar for the two pairs, ...201121767470
behavioural responses to human skin extracts and antennal phenotypes of sylvatic first filial generation and long rearing laboratory colony rhodnius prolixus.chagas disease is a major public health issue and is mainly spread by triatominae insects (hemiptera: reduviidae). rhodnius prolixus is the main vector species in northern south america. host-seeking behaviour in r. prolixus is mediated by different compounds that are produced by and emanate from the host or microbiota on the host's skin. we tested the behavioural responses of sylvatic first filial generation (f1) and colony insects to extracts of human skin with a dual choice olfactometer. in a ...201121739035
[evaluation of the toxic activity of the pyrethroid insecticides deltamethrin and lambdacyhalothrin in two panamanian field populations of rhodnius pallescens (hemíptera: reduviidae)].systematic evaluation of the susceptibility of disease vectors to insecticides permits the detection of the development of insecticide resistance over time. this is necessary to evaluate the effectiveness of control methods and to plan management strategies of the resistance.201122159478
phase contrast x-ray synchrotron imaging for assessing external and internal morphology of rhodnius prolixus.phc-sr-μct is a nondestructive technique that allows the microanatomical investigations and 3d images reconstructions. this technique is performed in blood sucker, rhodnius prolixus-one of the most important insect vectors of trypanosoma cruzi, ethiologic agent of chagas' disease in latin america-was able to provide excellent information about the microanatomy of the thorax and head allowing a new tool for further studies of development and physiology of triatomine by a non-invasive method of ob ...201122137661
Paratransgenic control of vector borne diseases.Conventional methodologies to control vector borne diseases with chemical pesticides are often associated with environmental toxicity, adverse effects on human health and the emergence of insect resistance. In the paratransgenic strategy, symbiotic or commensal microbes of host insects are transformed to express gene products that interfere with pathogen transmission. These genetically altered microbes are re-introduced back to the insect where expression of the engineered molecules decreases th ...201122110385
induced-antibacterial factors in the hemolymph of rhodnius prolixus. 20113075694
acidocalcisomes as calcium- and polyphosphate-storage compartments during embryogenesis of the insect rhodnius prolixus stahl.the yolk of insect eggs is a cellular domain specialized in the storage of reserve components for embryo development. the reserve macromolecules are stored in different organelles and their interactions with the embryo cells are mostly unknown. acidocalcisomes are lysosome-related organelles characterized by their acidic nature, high electron density and large content of polyphosphate bound to several cations. in this work, we report the presence of acidocalcisome-like organelles in eggs of the ...201122096545
the proctolin gene and biological effects of proctolin in the blood-feeding bug, rhodnius prolixus.we have reinvestigated the possible presence or absence of the pentapeptide proctolin in rhodnius prolixus and report here the cloning of the proctolin cdna. the transcript is expressed in the central nervous system (cns) and some peripheral tissues. the proctolin prepropeptide encodes a single copy of proctolin along with a possible proctolin-precursor-associated peptide. we have biochemically identified proctolin in cns extracts and shown its distribution using proctolin-like immunoreactivity. ...201122654816
transcriptome and gene expression profile of ovarian follicle tissue of the triatomine bug rhodnius prolixus.insect oocytes grow in close association with the ovarian follicular epithelium (ofe), which escorts the oocyte during oogenesis and is responsible for synthesis and secretion of the eggshell. we describe a transcriptome of ofe of the triatomine bug rhodnius prolixus, a vector of chagas disease, to increase our knowledge of the role of fe in egg development. random clones were sequenced from a cdna library of different stages of follicle development. the transcriptome showed high commitment to t ...201121736942
serotonin has kinin-like activity in stimulating secretion by malpighian tubules of the house cricket acheta domesticus.serotonin stimulates secretion by malpighian tubules (mt) of a number of insects, and functions as a diuretic hormone in rhodnius prolixus and in larval aedes aegypti. serotonin is here shown to be a potent stimulant of secretion by mt of the house cricket, acheta domesticus, with an apparent ec(50) of 9.4 nmol l(-1), although its diuretic activity is just 25% of the maximum achievable with either the native crf-related peptide, achdo-dh, or a crude extract of the corpora cardiaca. in this respe ...201120688119
characterization of the external female genitalia of six species of triatominae (hemiptera: reduviidade) by scanning electron microscopy.by macroscopic and microscopic dorsal side observation, it was noted that the ix and x segments of two species each of panstrongylus and triatoma terminate in an elongated way, whereas they terminate abruptly in the two species of rhodnius. scanning observation of the dorsal, ventral, lateral and posterior sides of the female genitalia of panstrongylus herreri, panstrongylus megistus, rhodnius colombiensis, rhodnius prolixus, triatoma infestans and triatoma vitticeps revealed that these six spec ...201020512241
isolation, expression analysis, and functional characterization of the first antidiuretic hormone receptor in insects.diuresis following blood-gorging in rhodnius prolixus is the major process leading to the transmission of chagas' disease. we have cloned the cdna of the first receptor known to be involved in an antidiuretic strategy in insects, a strategy that prevents diuresis. this receptor belongs to the insect capa receptor family known in other insects to be activated by peptides encoded within the capability gene. we characterize the expression profile in fifth-instars and find expression is localized to ...201020479227
neurohormones implicated in the control of malpighian tubule secretion in plant sucking heteropterans: the stink bugs acrosternum hilare and nezara viridula.plant sucking heteropteran bugs feed regularly on small amounts of k(+)-rich plant material, in contrast to their hematophagous relatives which imbibe large volumes of na(+)-rich blood. it was anticipated that this would be reflected in the endocrine control of malpighian tubule (mt) secretion. to explore this, neuroendocrine factors known to influence mt secretion were tested on mt of the pentatomid plant sucking stink bugs, acrosternum hilare and nezara viridula, and the results compared with ...201019772880
preliminary evidence of rhodnius prolixus (hemiptera: triatominae) attraction to human skin odour extracts.host-seeking behaviour displayed by the haematophagous triatomine rhodnius prolixus stål, 1859 is influenced by different cues involving heat, moisture and odours. concentrations of volatile odours present in human sweat and breath that activate, attract or non-attract triatomines were tested behaviourally with a double choice olfactometer in adults of r. prolixus. attraction of a mixture of substances carried by a controlled air-stream was established and compared with volatiles from human extr ...201019879853
trypanosoma rangeli: differential expression of ecto-phosphatase activities in response to inorganic phosphate starvation.in this work, we showed that living cells of trypanosoma rangeli express different ecto-phosphatase activities in response to different inorganic phosphate (pi) concentrations in the culture medium. the ecto-phosphatase activity from t. rangeli grown at low-pi concentration was inhibited by the increase of the ph, while the ecto-phosphatase of the cells grown at high pi concentration was not modulated by the change of the ph of the medium. okadaic acid inhibited only the ecto-phosphatase activit ...201020034491
discovery of a novel insect neuropeptide signaling system closely related to the insect adipokinetic hormone and corazonin hormonal systems.neuropeptides and their g protein-coupled receptors (gpcrs) play a central role in the physiology of insects. one large family of insect neuropeptides are the adipokinetic hormones (akhs), which mobilize lipids and carbohydrates from the insect fat body. other peptides are the corazonins that are structurally related to the akhs but represent a different neuropeptide signaling system. we have previously cloned an orphan gpcr from the malaria mosquito anopheles gambiae that was structurally inter ...201020068045
trypanosoma cruzi: synergistic cytotoxicity of multiple amphipathic anti-microbial peptides to t. cruzi and potential bacterial hosts.the parasite trypanasoma cruzi is responsible for chagas disease and its triatomine vector, rhodnius prolixus, has a symbiotic relationship with the soil bacterium, rhodococcus rhodnii. r. rhodnii that was previously genetically engineered to produce the anti-microbial peptide, cecropin a was co-infected with t. cruzi into r. prolixus resulting in clearance of the infectious t. cruzi in 65% of the vectors. similar anti-microbial peptides have been isolated elsewhere and were studied for differen ...201020206169
cytogenetics and genome evolution in the subfamily triatominae (hemiptera, reduviidae).the subfamily triatominae (hemiptera, reduviidae), vectors of chagas disease, includes over 140 species. karyotypic information is currently available for 80 of these species. this paper summarizes the chromosomal variability of the subfamily and how it may reveal aspects of genome evolution in this group. the triatominae present a highly conserved chromosome number. all species, except 3, present 20 autosomes. the differences in chromosome number are mainly caused by variation in the number of ...201020407223
a role for host-parasite interactions in the horizontal transfer of transposons across phyla.horizontal transfer (ht), or the passage of genetic material between non-mating species, is increasingly recognized as an important force in the evolution of eukaryotic genomes. transposons, with their inherent ability to mobilize and amplify within genomes, may be especially prone to ht. however, the means by which transposons can spread across widely diverged species remain elusive. here we present evidence that host-parasite interactions have promoted the ht of four transposon families betwee ...201020428170
primary culture of rhodnius prolixus (hemiptera: reduviidae) salivary gland cells.in the present paper, we developed a primary culture of rhodnius prolixus salivary gland and main salivary canal cells. cells remained viable in culture for 30 days. three types of cells were indentified in the salivary gland cultures, with binuclear cells being the most abundant. the supernatants of salivary cultures contained mainly 16-24 kda proteins and presented anticoagulant and apyrase activities. secretion vesicles were observed budding from the cellular monolayer of the main salivary ca ...201020428670
morphometry and morphology of the antennae of panstrongylus megistus burmeister, rhodnius neglectus lent, rhodnius prolixus stal and triatoma vitticeps stal (hemiptera: reduviidae).the length of the four right antennal segments from nymphs and adults of panstrongylus megistus burmeister, rhodnius neglectus lent, rhodnius prolixus stal and triatoma vitticeps stal were measured. the length of the antennal segments of the adults of all four species, 4th and 5th instars of p. megistus, and 5th instar of r. neglectus and r. prolixus followed the same pattern: 2nd>3rd>4th>1st. the pattern of 1st and 2nd instars of p. megistus was: 4th>3rd>2nd>1st. for 3rd instars of p. megistus, ...201020498958
feeding through artificial membranes reduces fecundity for females of the blood-feeding insect, rhodnius prolixus.the blood-feeding insect, rhodnius prolixus, has been raised in the laboratory for close to 100 years. various feeding techniques have been employed ranging from the use of warm-blooded hosts, to the use of previously collected blood offered through artificial membranes. this study compared the fecundity in mated and unmated females fed rabbit blood directly from the shaved belly of a rabbit to that of females fed defibrinated rabbit blood through an artificial membrane. these results confirm pr ...201020513058
commercial coconut palm as an ecotope of chagas disease vectors in north-eastern venezuela.there are few reports of coccus nucifera (palmae) infestation by triatomines (hemiptera, reduviidae, triatominae), vectors of trypanosoma cruzi (kinetoplastida: trypanosomatidae), the causal agent of american trypanosomiasis. the aim of this study was to determine if this palm is an appropriate ecotope for rhodnius prolixus and triatoma maculata, the main vectors in venezuela.201020539044
a standardizable protocol for infection of rhodnius prolixus with trypanosoma rangeli, which mimics natural infections and reveals physiological effects of infection upon the insect.trypanosoma rangeli is a protozoan parasite that shares hosts - mammals and triatomines - with trypanosoma cruzi, the etiological agent of chagas disease. although t. rangeli is customarily considered to be non-pathogenic to human hosts, it is able to produce pathologies in its invertebrate hosts. however, advances are hindered by a lack of standardization of infection procedures and these pathologies need documentation. to establish a suitable, and standardizable, infection protocol, the durati ...201020546751
cuticular plasticization in the tick, amblyomma hebraeum (acari: ixodidae): possible roles of monoamines and cuticular ph.the degree of plasticization of the alloscutal cuticle of a 'hard' (ixodid) tick, amblyomma hebraeum, and a 'soft' (argasid) tick, ornithodoros moubata, was assessed throughout the blood-feeding period. cuticle viscosity was calculated from rate of creep of cuticle under constant load using a maxwell model. feeding-related plasticization (i.e. increased rate of extension under a constant load) occurred in a. hebraeum but not in o. moubata. maxwell viscosity of unfed a. hebraeum cuticle was relat ...201020675552
validation of a less invasive blood sampling technique in rabies serology using reduviid bugs (triatominae, hemiptera).during serologic rabies surveys, bleeding is often difficult or almost impossible in small or endangered mammals such as bats. therefore, the usefulness of an alternative, less invasive technique--that is, the use of blood-sucking reduviid bugs (dipetalogaster maximus and rhodnius prolixus)--was investigated. bugs were used in combination with a conventional method (retro-orbitale bleeding) to obtain blood samples from the same individual nmri-mice (mus musculus) vaccinated against rabies. rabie ...201020722255
genetic variability and phylogenetic relationships within trypanosoma cruzi i isolated in colombia based on miniexon gene sequences.phylogenetic studies of trypanosoma cruzi have identified the existence of two groups: t. cruzi i and t. cruzi ii. there are aspects that still remain unknown about the genetic variability within the t. cruzi i group. given its epidemiological importance, it is necessary to have a better understanding of t. cruzi transmission cycles. our purpose was to corroborate the existence of haplotypes within the t. cruzi i group and to describe the genetic variability and phylogenetic relationships, based ...201020798881
paralytic activity of lysophosphatidylcholine from saliva of the waterbug belostoma anurum.lysophosphatidylcholine (lpc) is a major bioactive lipid that is enzymatically generated by phospholipase a(2) (pla(2)). previously, we showed that lpc is present in the saliva of the blood-sucking hemipteran rhodnius prolixus and modulates cell-signaling pathways involved in vascular biology, which aids blood feeding. here, we show that the saliva of the predator insect belostoma anurum contains a large number of lipids with lpc accounting for 25% of the total phospholipids. a pla(2) enzyme lik ...201020833923
nitrophorin 2, a factor ix(a)-directed anticoagulant, inhibits arterial thrombosis without impairing haemostasis.nitrophorin 2 (np2) is a 20 kda lipocalin identified in the salivary gland of the blood sucking insect, rhodnius prolixus. it functions as a potent inhibitor of the intrinsic pathway of coagulation upon binding to factor ix (fix) or fixa. herein we have investigated the in vivo antithrombotic properties of np2. surface plasmon resonance assays demonstrated that np2 binds to rat fix and fixa with high affinities (kd = 43 and 47 nm, respectively), and prolongs the aptt without affecting the pt. in ...201020838739
sn-protoporphyrin inhibits both heme degradation and hemozoin formation in rhodnius prolixus midgut.hematophagy is a feeding habit that involves the ingestion of huge amounts of heme. the hematophagous hemipteran rhodnius prolixus evolved many genetic resources to protect cells against heme toxicity. the primary barrier against the deleterious effects of heme is the aggregation of heme into hemozoin in the midgut lumen. hemozoin formation is followed by the enzymatic degradation of heme by means of a unique pathway whose end product is dicysteinyl-biliverdin ix-γ (rhodnius prolixus biliverdin, ...201020851767
[genetic differentiation of three colombian populations of triatoma dimidiata (heteroptera: reduviidae) by nd4 mitochondrial gene molecular analysis].triatoma dimidiata is the second most important vector of chagas disease in colombia after rhodnius prolixus. population genetic studies are essential for the adequate design and implementation of vector control and surveillance strategies.201020890568
neuropeptide precursor gene discovery in the chagas disease vector rhodnius prolixus.we show a straightforward workflow combining homology search in rhodnius prolixus genome sequence with cloning by rapid amplification of cdna ends and mass spectrometry. we have identified 32 genes and their transcripts that encode a number of neuropeptide precursors leading to 194 putative peptides. we validated by mass spectrometry 82 of those predicted neuropeptides in the brain of r. prolixus to achieve the first comprehensive genomic, transcriptomic and neuropeptidomic analysis of an insect ...201020958806
the control of malpighian tubule secretion in a predacious hemipteran insect, the spined soldier bug podisus maculiventris (heteroptera, pentatomidae).spined soldier bugs, podisus maculiventris, are heteropteran insects that feed voraciously on other insects, particular the soft bodied larval forms of lepidoptera and coleoptera. the response of p. maculiventris malpighian tubules (mts) to serotonin and known diuretic and antidiuretic peptides has been investigated, and is compared with that of mt from the hematophagous and phytophagous heteropteran bugs rhodnius prolixus and acrosternum hilare, respectively. a crf-related peptide diuretic horm ...201021093508
effects of platelet-activating factor on the interaction of trypanosoma cruzi with rhodnius prolixus.we investigated the effects of platelet-activating factor (paf) on the interaction of trypanosoma cruzi with rhodnius prolixus. the parasites (epimastigotes) were treated with paf and/or web 2086 (paf antagonist) for 1 h prior to the interaction experiments. paf stimulated both in vivo and ex vivo interactions between t. cruzi and r. prolixus while web 2086 abrogated these effects. paf-treated epimastigotes also showed an increase in surface negativity and in the amount of surface sialic acid. n ...201021161276
flight initiation by male rhodnius prolixus is promoted by female odors.several triatomine bug species utilize chemical cues for sexual communication. we tested whether female or male rhodnius prolixus, a vector of chagas disease, produce volatile chemicals that elicit flight responses from conspecifics, and then isolated the source of the chemical. males confronted with an airstream containing female odors showed a significantly greater take-off frequency compared to a blank airstream or an airstream with male odors. in contrast, females exhibited similar take-off ...201020352301
two capa-genes are expressed in the neuroendocrine system of rhodnius prolixus.capa-peptides have been isolated from a broad range of insect species and are typical of the neurosecretory system of the abdominal ventral nerve cord. in rhodnius prolixus, which is known to transmit chagas' disease, capa-peptides have potent antidiuretic effects. recently, two capa-genes were isolated from this hemipteran insect; it was the first description of the occurrence of multiple capa-genes from a single insect species. the expression of peptides from one of these capa-genes was confir ...201019778561
unprecedented peroxidase-like activity of rhodnius prolixus nitrophorin 2: identification of the [feiv=o por•]+ and [feiv=o por](tyr38•) intermediates and their role(s) in substrate oxidation.we have identified a novel enzymatic reaction for nitrophorin 2 (np2), a heme protein previously characterized as a nitric oxide carrier in the saliva of the rhodnius prolixus insect. np2 exhibited levels of peroxidase activity comparable to those of the bifunctional peroxidases (katgs), despite their heme pocket structural differences (heme ruffling, tyr38 and tyr85 in hydrogen bonding interactions with the propionates in np2). the intermediates of the peroxidase-like reaction of np2 were ident ...201020726527
formation of the complex of nitrite with the ferriheme b beta-barrel proteins nitrophorin 4 and nitrophorin 7.the interaction of ferriheme proteins with nitrite has recently attracted interest as a source for no or other nitrogen oxides in mammalian physiology. however, met-hemoglobin (methb), which was suggested as a key player in this process, does not convert nitrite unless small amounts of no are added in parallel. we have recently reported that, in contrast, nitrophorins (nps) convert nitrite as the sole substrate to form no even at ph 7.5, which is an unprecedented case among ferrihemes [he, c., a ...201020524697
phenol oxidases from rhodnius prolixus: temporal and tissue expression pattern and regulation by ecdysone.rhodnius prolixus 5th instar nymphs have significant po enzymatic activity in the anterior midgut, fat body and hemolymph. the tissue with the major amount of po activity is the anterior midgut while those with higher specific activities are the fat body and hemolymph. in this work the temporal pattern of po enzymatic activity in different tissues was investigated. in fat body, po peaks occur at 7, 12 and 16 days after a blood meal. in hemolymph, po diminishes until day 7, and then recovers by d ...201020361973
jack bean urease alters serotonin-induced effects on rhodnius prolixus anterior midgut.urease isoforms from jack bean seeds are toxic to insects, and this entomotoxic effect is mostly due to the release of a peptide by insect digestive enzymes. we previously demonstrated that jack bean urease (jbu) has antidiuretic effects on rhodnius prolixus malpighian tubules, decreasing the serotonin-stimulated secretion of fluid. now, we evaluate the toxicity of the intact jbu and its effect on r. prolixus anterior midgut, to further elucidate the mechanism of action of jbu in insects. jbu de ...201020223243
the circadian timing system in the brain of the fifth larval instar of rhodnius prolixus (hemiptera).the brain of larval rhodnius prolixus releases neurohormones with a circadian rhythm, indicating that a clock system exists in the larval brain. larvae also possess a circadian locomotor rhythm. the present paper is a detailed analysis of the distribution and axonal projections of circadian clock cells in the brain of the fifth larval instar. clock cells are identified as neurons that exhibit circadian cycling of both per and tim proteins. a group of eight lateral clock neurons (lns) in the prox ...201020151359
serotonin regulates an acyl-coa-binding protein (acbp) gene expression in the midgut of rhodnius prolixus.acyl-coa esters have many intracellular functions, acting as energy source, substrate for metabolic processes and taking part in cell signaling. the acyl-coa-binding protein (acbp), a highly conserved 10 kda intracellular protein, binds long- and medium-chain acyl-coa esters with very high affinity, directing them to specific metabolic routes and protecting them from hydrolysis. an acbp gene sequence was identified in the genome of rhodnius prolixus. this acbp gene (rpacbp-1) was expressed in al ...201020079838
effects of the cyclopeptide mycotoxin destruxin a on the malpighian tubules of rhodnius prolixus (stål).the production of peptide toxins by entomopathogenic fungi during the infection process plays critical roles in pathogenesis. to gain insight into the mechanism of action of these mycotoxins on insect internal organs, we have evaluated the effects of destruxin a, a cyclic peptide produced by metarhizium anispliae, on rhodnius prolixus malpighian tubules measuring fluid secretion rate, transepithelial electrical potential (tep), ph and ion composition of secreted fluid, and atp content. destruxin ...201020060849
on the physico-chemical and physiological requirements of hemozoin formation promoted by perimicrovillar membranes in rhodnius prolixus midgut.triatomine insects are obligatory blood-feeders that detoxify most of the hemoglobin-derived heme through its crystallization into hemozoin (hz). previous evidence demonstrates the key role of midgut perimicrovillar membranes (pmvm) on heme crystallization in triatomines. here, we investigated some of the physico-chemical and physiological aspects of heme crystallization induced by rhodnius prolixus pmvm. hz formation in vitro proceeded optimally at ph 4.8 and 28 degrees c, apparently involving ...201020060043
the antidiuretic neurohormone rhoprcapa-2 downregulates fluid transport across the anterior midgut in the blood-feeding insect rhodnius prolixus.osmotic balance in insects is regulated by the excretory system, consisting of malpighian tubules and the gut under the control of diuretic and antidiuretic factors. terrestrial insects must conserve water, and antidiuresis is the norm, only interrupted by brief diuretic periods. surprisingly, little is known about antidiuresis in insects. two antidiuretic strategies have been described. the first antidiuretic mechanism involves the reabsorption of fluid from the primary urine in the hindgut. mo ...201020007522
inorganic polyphosphate inhibits an aspartic protease-like activity in the eggs of rhodnius prolixus (stahl) and impairs yolk mobilization in vitro.inorganic polyphosphate (poly p) is a polymer of phosphate residues that has been shown to act as modulator of some vertebrate cathepsins. in the egg yolk granules of rhodnius prolixus, a cathepsin d is the main protease involved in yolk mobilization and is dependent on an activation by acid phosphatases. in this study, we showed a possible role of poly p stored inside yolk granules on the inhibition of cathepsin d and arrest of yolk mobilization during early embryogenesis of these insects. enzy ...201019957302
a second gene encodes the anti-diuretic hormone in the insect, rhodnius prolixus.in the haematophagous insect, rhodnius prolixus, a rapid diuresis following engorgement of vertebrate blood is under the control of two main diuretic hormones: a corticotropin-releasing factor (crf)-related peptide andserotonin (5ht). a cap2b (capa)-related peptide is involved in the termination of this diuresis, and we have recently identified a gene, now referred to as rhoprcapa-alpha, encoding capa peptides in r. prolixus. here we identify a second gene, rhoprcapa-beta, which also encodes cap ...201019931590
transitions in insect respiratory patterns are controlled by changes in metabolic rate.we examined the respiratory patterns of rhodnius prolixus and gromphadorhina portentosa as metabolic rates varied with temperature to determine whether insects transition from discontinuous (dgc), cyclical and continuous respiration as a response to increasing aerobic demand. using flow through respirometry we: (1) determined the effects of temperature on metabolic rate; (2) objectively defined periods of spiracular closure; (3) observed whether there was a correlation between metabolic rate and ...201019523955
peptides and serotonin control feeding-related events in rhodnius prolixus.rhodnius prolixus periodically gorges on a blood meal that could compromise salt and water balance. this, however, is prevented by rapid production of urine within minutes of feeding. the malpighian tubules increase their rate of secretion 1,000 fold leading to the production of a hypo-osmotic urine that is high in nacl content. feeding and post-prandial diuresis in r. prolixus are tightly coordinated events, involving a variety of neurons within the central nervous system. the present review co ...200919482642
biological activity of diuretic factors on the anterior midgut of the blood-feeding bug, rhodnius prolixus.probing of a host and ingestion of a blood-meal in a fifth instar rhodnius prolixus results in a cascade of tightly integrated events, including salivary gland secretion, plasticization of the abdominal cuticle, increased ion and water movement across the anterior midgut (crop) and malpighian tubules (which rapidly produce urine) and the regular expulsion of urine from the hindgut. in this study we have focussed on the role of the anterior midgut during the rapid postprandial diuresis. the huge ...200919408362
protein dynamics of a beta-sheet protein.rhodnius prolixus nitrophorin 4 (abbreviated np4) is an almost pure beta-sheet heme protein. its dynamics is investigated by x-ray structure determination at eight different temperatures from 122 to 304 k and by means of mössbauer spectroscopy. a comparison of this beta-sheet protein with the pure alpha-helical protein myoglobin (abbreviated mbmet) is performed. the mean square displacement derived from the mössbauer spectra increases linearly with temperature below a characteristic temperature ...200919271215
effect of mutation of carboxyl side-chain amino acids near the heme on the midpoint potentials and ligand binding constants of nitrophorin 2 and its no, histamine, and imidazole complexes.nitrophorins (nps) are a group of no-carrying heme proteins found in the saliva of a blood-sucking insect from tropical central and south america, rhodnius prolixus, the "kissing bug". no is kept stable for long periods of time by binding it as an axial ligand to a ferriheme center. the fact that the nitrophorins are stabilized as fe(iii)-no proteins is a unique property because most heme proteins are readily autoreduced by excess no and bind no to the fe(ii) heme irreversibly (k(d)s in the pico ...200919175316
metabolic rate controls respiratory pattern in insects.the majority of scientific papers on the subject of respiratory patterns in insects have dealt with the discontinuous gas-exchange cycle (dgc). the dgc is characterized by the release of bursts of co(2) from the insect, followed by extended periods of spiracular closure. several hypotheses have been put forward to explain the evolutionary origin and physiological function of this unusual respiratory pattern. we expand upon one of these (the oxidative damage hypothesis) to explain not only the oc ...200919151217
neuroendocrine control of ionic homeostasis in blood-sucking insects.the pioneering work of simon maddrell established that the rapid postprandial diuresis of the haematophagous insect rhodnius prolixus is controlled by a diuretic hormone and demonstrated the role of the malpighian tubules in meeting the volumic, osmotic and ionic challenges posed by an enormous blood meal. a number of diuretic and antidiuretic hormones that control secretion of primary urine by malpighian tubules have now been identified, but little is known of the interplay between these hormon ...200919151213
too much of a good thing: how insects cope with excess ions or toxins in the diet.much of our understanding of the ionoregulatory and excretory physiology of blood-feeding insects can be traced to a series of papers by simon maddrell and colleagues in the 1970s and 1980s. these studies of the malpighian (renal) tubules of rhodnius prolixus revealed a number of physiological adaptations to the short-term and long-term stresses associated with blood feeding. more recent electrophysiological studies using voltage- and ion-selective microelectrodes have extended our understanding ...200919151211
cytochemical characterization of microvillar and perimicrovillar membranes in the posterior midgut epithelium of rhodnius prolixus.perimicrovillar membranes (pmm) are structures present on the surface of midgut epithelial cells of the hematophagous insect, rhodnius prolixus. they cover the microvilli and are especially evident 10 days after blood meal, providing the compartmentalization of the enzymatic processes in the intestinal microenvironment. using an enzyme cytochemical approach, mg2+-atpase and ouabain-sensitive na+k+-atpase activities were observed in the plasma (or microvillar) membrane (mm) of midgut cells and in ...200918602023
ecdysteroid receptor (ecr) is associated with microtubules and with mitochondria in the cytoplasm of prothoracic gland cells of rhodnius prolixus (hemiptera).we have shown previously that ecr in larval rhodnius is present in the cytoplasm of various cell types and undergoes daily cycling in abundance in the cytoplasm (vafopoulou and steel, 2006. cell tissue res 323:443-455). it is unknown which organelles are associated with ecr. here, we report that cytoplasmic ecr in prothoracic gland cells is associated with both microtubules and mitochondria, and discuss the implications for both nuclear and non-genomic actions of ecr. ecr was localized immunohis ...200919847923
cloning and characterization of dorsal homologues in the hemipteran rhodnius prolixus.rhodnius prolixus is an ancient haematophagous hemipteran insect capable of mounting a powerful immune response. this response is transcriptionally regulated in part by transcription factors of the rel/nuclear factor kappa b (rel/nf-kappab) family. we have cloned and characterized three members of this transcription factor family in this insect. dorsal 1a is primarily expressed in early developmental stages. in contrast, dorsal 1b and 1c, both differentially spliced products of dorsal 1a, are ex ...200919754745
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