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alba proteins are stage regulated during trypanosome development in the tsetse fly and participate in differentiation.the protozoan parasite trypanosoma brucei is responsible for sleeping sickness and alternates between mammal and tsetse fly hosts, where it has to adapt to different environments. we investigated the role of two members of the alba family, which encodes hypothetical rna-binding proteins conserved in most eukaryotes. we show that alba3/4 proteins colocalize with the dhh1 rna-binding protein and with a subset of poly(a+) rna in stress granules upon starvation. depletion of alba3/4 proteins by rna ...201121965287
lipophorin acts as a shuttle of lipids to the milk gland during tsetse fly pregnancy.during pregnancy in the viviparous tsetse fly, lipid mobilization is essential for the production of milk to feed the developing intrauterine larva. lipophorin (lp) functions as the major lipid transport protein in insects and closely-related arthropods. in this study, we assessed the role of lp and the lipophorin receptor (lpr) in the lipid mobilization process during tsetse reproduction. we identified single gene sequences for gmmlp and gmmlpr from the genome of glossinamorsitansmorsitans, and ...201121875592
Cryptic diversity within the major trypanosomiasis vector Glossina fuscipes revealed by molecular markers.The tsetse fly Glossina fuscipes s.l. is responsible for the transmission of approximately 90% of cases of human African trypanosomiasis (HAT) or sleeping sickness. Three G. fuscipes subspecies have been described, primarily based upon subtle differences in the morphology of their genitalia. Here we describe a study conducted across the range of this important vector to determine whether molecular evidence generated from nuclear DNA (microsatellites and gene sequence information), mitochondrial ...201121858237
Glycolysis in the african trypanosome: targeting enzymes and their subcellular compartments for therapeutic development.Subspecies of the African trypanosome, Trypanosoma brucei, which cause human African trypanosomiasis, are transmitted by the tsetse fly, with transmission-essential lifecycle stages occurring in both the insect vector and human host. During infection of the human host, the parasite is limited to using glycolysis of host sugar for ATP production. This dependence on glucose breakdown presents a series of targets for potential therapeutic development, many of which have been explored and validated ...201122091393
The Enhancer of split complex arose prior to the diversification of schizophoran flies and is strongly conserved between Drosophila and stalk-eyed flies (Diopsidae).ABSTRACT: BACKGROUND: In Drosophila, the Enhancer of Split complex (E(spl)-C) comprises 11 bHLH and Bearded genes that function during Notch signaling to repress proneural identity in the developing peripheral nervous system. Comparison with other insects indicates that the basal state for Diptera is a single bHLH and Bearded homolog and that the expansion of the gene complex occurred in the lineage leading to Drosophila. However, comparative genomic data from other fly species that would eluci ...201122151427
Human African trypanosomiasis in endemic populations and travellers.Human African trypanosomiasis (HAT) or sleeping sickness is caused by the protozoan parasites Trypanosoma brucei (T.b.) gambiense (West African form) and T.b. rhodesiense (East African form) that are transmitted by the bite of the tsetse fly, Glossina spp.. Whereas most patients in endemic populations are infected with T.b. gambiense, most tourists are infected with T.b. rhodesiense. In endemic populations, T.b. gambiense HAT is characterized by chronic and intermittent fever, headache, pruritus ...201121901632
experimental evaluation of xenodiagnosis to detect trypanosomes at low parasitaemia levels in infected hosts.in human african trypanosomosis (hat) endemic areas, there are a number of subjects that are positive to serological tests but in whom trypanosomes are difficult to detect with the available parasitological tests. in most cases and particularly in west africa, these subjects remain untreated, thus posing a fundamental problem both at the individual level (because of a possible lethal evolution of the disease) and at the epidemiological level (since they are potential reservoirs of trypanosomes). ...201122091459
the chemistry and biology of trypanosomal trans-sialidases: virulence factors in chagas disease and sleeping sickness.trans-sialidases constitute a special group of the sialidase family. they occur in some trypanosome species and, in a unique reversible reaction, transfer sialic acids from one glycosidic linkage with galactose (donor) to another galactose (acceptor), to form (α2-3)-sialyl linkages. trypanosomes cause such devastating human diseases as chagas disease in south america (trypanosoma cruzi) or sleeping sickness in africa (trypanosoma brucei). the trans-sialidases strongly contribute to the pathogeni ...201121956798
[ivory coast uprising and returning burkinabe immigrants: evaluation of the risk for reemergence of sleeping sickness in burkina faso].following the sociopolitical unrest that occurred in ivory coast in 2002, 360,000 burkinabe immigrants returned to burkina faso that was the epicenter of sleeping sickness last century and is now thought to be free of autochthonous transmission. the purpose of this study was to determine if the massive return of immigrants from human african trypanosomiasis (hat) endemic areas of ivory coast to areas in burkina faso where the vector (tsetse fly) is currently present could lead to re-emergence of ...201021520653
tbunc119 and its binding protein complex are essential for propagation, motility, and morphogenesis of trypanosoma brucei procyclic form cells.flagellum-mediated motility of trypanosoma brucei is considered to be essential for the parasite to complete stage development in the tsetse fly vector, while the mechanism by which flagellum-mediated motility is controlled are not fully understood. we thus compared t. brucei whole gene products (amino acid sequence) with caenorhabditis elegans unc (uncoordinated) proteins, in order to find uncharacterized motility-related t. brucei genes. through in silico analysis, we found 88 gene products wh ...201021203515
evolutionary genomics of glossina morsitans immune-related clip domain serine proteases and serine protease inhibitors.several species of haematophagous tsetse flies (genus glossina) are vectors for trypanosomes, the parasitic protozoans that cause human african trypanosomiasis (hat). although there was a reduced incidence of hat in the mid 1960s, decreased disease surveillance has led to a resurgence of hat in sub-saharan africa. despite being efficient vectors for hat transmission, the prevalence of g. morsitans infection by trypanosomes in the wild is surprisingly minimal. the precise mechanisms by which g. m ...201021055483
theoretical levels of control as a function of mean temperature and spray efficacy in the aerial spraying of tsetse fly.the hypothetical impact of aerial spraying on tsetse fly populations is investigated. spray cycles are scheduled at intervals two days short of the first interlarval period and halted once the last of the female flies that originated from pre-spray-deposited pupae have been sprayed twice. the effect of temperature on the aerial spraying of tsetse, through its reproductive cycle and general population dynamics, is of particular interest, given that cooler weather is preferred for the settling of ...201021087595
fine structure of the female reproductive system in a viviparous insect, glossina morsitans morsitans (diptera, glossinidae).the female reproductive system of the tsetse fly glossina morsitans morsitans is analysed by scanning electron microscopy (sem). the study focuses in particular on the choriothete, a peculiar uterine structure involved in the viviparous mode of reproduction of glossina morsitans morsitans. under light microscopy, the choriothete appears formed by numerous tongue-like folds projecting towards the uterine lumen and lined by a thin cuticle. sem analysis highlights for the first time a distinctive n ...201021094964
tsetse fly control and trypanosomiasis in africa, quo vadis?national and international efforts to eradicate tsetse fly-borne human and animal trypanosomiasis are critically evaluated, and possible reasons for their failure in many cases are discussed. some formerly performed campaigns in specific areas with positive results cannot be taken as examples to solve the main problems. in future, a significant reduction of trypanosomiasis cases will be possible to achieve only if a concerted long-term pan-african approach, based on financial security, the conti ...201021104211
functional analysis of the twin-arginine translocation pathway in sodalis glossinidius, a bacterial symbiont of the tsetse fly.this study demonstrates a functional twin-arginine (tat) translocation pathway present in the tsetse fly symbiont sodalis glossinidius and its potential to export active heterologous proteins to the periplasm. functionality was demonstrated using green fluorescent protein (gfp) fused to the tat signal peptide of escherichia coli trimethylamine n-oxide reductase (tora).201021148698
serratia glossinae sp. nov., isolated from the midgut of the tsetse fly glossina palpalis gambiensis.we report the isolation of a novel bacterium, strain c1(t), from the midgut of the tsetse fly glossina palpalis gambiensis, one of the vector insects responsible for transmission of the trypanosomes that cause sleeping sickness in sub-saharan african countries. strain c1(t) is a motile, facultatively anaerobic, rod-like bacterium (0.8-1.0 microm in diameter; 2-6 microm long) that grows as single cells or in chains. optimum growth occurred at 25-35 degrees c, at ph 6.7-8.4 and in medium containin ...201019667382
transmissibility, by glossina morsitans morsitans, of trypanosoma congolense strains during the acute and chronic phases of infection.in order to verify whether chronic trypanosomal infections can affect the transmissibility of trypanosoma congolense by tsetse flies, batches of glossina morsitans morsitans were fed on mice infected with the same level of parasitemia (10(8.1)trypanosomes/ml of blood) of two cloned low virulent t. congolense strains during the acute and the chronic phases of infection. results showed that the proportions of procyclic infections in flies that were fed during the acute phase (32.6% and 45.4% for i ...201019765543
molecular characterization of the key switch f provides a basis for understanding the rapid divergence of the sex-determining pathway in the housefly.the housefly, musca domestica, is an excellent model system to study the diversification of the pathway that specifies the sexual fate. a number of different mechanisms have been described in the housefly, which reflects in part the broad diversity of sex-determining strategies used in insects. in this study we present the molecular identification and characterization of f, which acts as the master switch in the housefly pathway. we provide evidence that f corresponds to the transformer ortholog ...201019841093
tripartite interactions between tsetse flies, sodalis glossinidius and trypanosomes--an epidemiological approach in two historical human african trypanosomiasis foci in cameroon.epidemiological surveys were conducted in two historical human african trypanosomiasis foci in south cameroon, bipindi and campo. in each focus, three sampling areas were defined. in bipindi, only glossina palpalis was identified, whereas four species were identified in campo, g. palpalis being highly predominant (93%). for further analyses, 75 flies were randomly chosen among the flies trapped in each of the six villages. large and statistically significant differences were recorded between bot ...201019879380
trypanosoma brucei: reduction of gpi-phospholipase c protein during differentiation is dependent on replication of newly transformed cells.the protozoan parasite trypanosoma brucei lives in the bloodstream of vertebrates or in a tsetse fly. expression of a gpi-phospholipase c polypeptide (gpi-plcp) in the parasite is restricted to the bloodstream form. events controlling the amount of gpi-plcp expressed during differentiation are not completely understood. our metabolic "pulse-chase" analysis reveals that gpi-plcp is stable in bloodstream form. however, during differentiation of bloodstream to insect stage (procyclic) t. brucei, tr ...201020109448
molecular characterization of two novel milk proteins in the tsetse fly (glossina morsitans morsitans).milk proteins are an essential component of viviparous reproduction in the tsetse fly. milk proteins are synthesized in and secreted from the milk gland tissue and constitute 50% of the secretions from which the intrauterine larva derives its nourishment. to understand milk protein function and regulation during viviparous reproduction, milk proteins need to be identified and characterized.201020136662
the protease resistant surface (prs) glycoconjugate from trypanosoma congolense has an inositol-acylated glycosylphosphatidylinositol anchor, containing a significant proportion of myristate at the sn-2 position.in the tsetse fly, the surface of trypanosoma congolense parasites is covered by a dense layer of glycosylphosphatidylinositol (gpi)-anchored molecules. these include epgengt procyclin and protease resistant surface molecule (prs), as well as congolense epimastigote-specific protein, cesp, and glutamic acid- and alanine-rich protein (garp). the gpi structures of epgengt and garp have been partially elucidated, but very little is known about prs. we now purified prs and analyzed its gpi lipid str ...201020138924
a cross-sectional study of trypanosomosis and its vectors in donkeys and mules in northwest ethiopia.a preliminary study was conducted in january 2009 in four peasant associations (pas) selected from two districts in benishangul gumuz regional state, northwest ethiopia to investigate the prevalence and species of trypanosomes infecting donkeys and mules and identify the fly vectors playing a role in the transmission of trypanosomosis. blood samples were collected from a total of 334 donkeys and 52 mules and examined by dark ground/phase contrast buffy coat technique and giemsa-stained blood sme ...201020143093
a trk/hkt-type k+ transporter from trypanosoma brucei.the molecular mechanisms of k(+) homeostasis are only poorly understood for protozoan parasites. trypanosoma brucei subsp. parasites, the causative agents of human sleeping sickness and nagana, are strictly extracellular and need to actively concentrate k(+) from their hosts' body fluids. the t. brucei genome contains two putative k(+) channel genes, yet the trypanosomes are insensitive to k(+) antagonists and k(+) channel-blocking agents, and they do not spontaneously depolarize in response to ...201020190075
evidence that low endocytic activity is not directly responsible for human serum resistance in the insect form of african trypanosomes.abstract:201020205710
transcriptome analysis of reproductive tissue and intrauterine developmental stages of the tsetse fly (glossina morsitans morsitans).tsetse flies, vectors of african trypanosomes, undergo viviparous reproduction (the deposition of live offspring). this reproductive strategy results in a large maternal investment and the deposition of a small number of progeny during a female's lifespan. the reproductive biology of tsetse has been studied on a physiological level; however the molecular analysis of tsetse reproduction requires deeper investigation. to build a foundation from which to base molecular studies of tsetse reproductio ...201020214793
tsetse ep protein protects the fly midgut from trypanosome establishment.african trypanosomes undergo a complex developmental process in their tsetse fly vector before transmission back to a vertebrate host. typically, 90% of fly infections fail, most during initial establishment of the parasite in the fly midgut. the specific mechanism(s) underpinning this failure are unknown. we have previously shown that a glossina-specific, immunoresponsive molecule, tsetse ep protein, is up regulated by the fly in response to gram-negative microbial challenge. here we show by kn ...201020221444
identification of a tsetse fly salivary protein with dual inhibitory action on human platelet aggregation.tsetse flies (glossina sp.), the african trypanosome vectors, rely on anti-hemostatic compounds for efficient blood feeding. despite their medical importance, very few salivary proteins have been characterized and functionally annotated.201020351782
an insight into the sialome of glossina morsitans morsitans.blood feeding evolved independently in worms, arthropods and mammals. among the adaptations to this peculiar diet, these animals developed an armament of salivary molecules that disarm their host's anti-bleeding defenses (hemostasis), inflammatory and immune reactions. recent sialotranscriptome analyses (from the greek sialo = saliva) of blood feeding insects and ticks have revealed that the saliva contains hundreds of polypeptides, many unique to their genus or family. adult tsetse flies feed e ...201020353571
nutrient provisioning facilitates homeostasis between tsetse fly (diptera: glossinidae) symbionts.host-associated microbial interactions may involve genome complementation, driving-enhanced communal efficiency and stability. the tsetse fly (diptera: glossinidae), the obligate vector of african trypanosomes (trypanosoma brucei subspp.), harbours two enteric gammaproteobacteria symbionts: wigglesworthia glossinidia and sodalis glossinidius. host coevolution has streamlined the wigglesworthia genome to complement the exclusively sanguivorous tsetse lifestyle. comparative genomics reveal that th ...201020356887
effects of flow rate and temperature on cyclic gas exchange in tsetse flies (diptera, glossinidae).air flow rates may confound the investigation and classification of insect gas exchange patterns. here we report the effects of flow rates (50, 100, 200, 400 ml min(-1)) on gas exchange patterns in wild-caught glossina morsitans morsitans from zambia. at rest, g. m. morsitans generally showed continuous or cyclic gas exchange (cge) but no evidence of discontinuous gas exchange (dge). flow rates had little influence on the ability to detect cge in tsetse, at least in the present experimental setu ...201020399350
the trypanosoma brucei life cycle switch tbptp1 is structurally conserved and dephosphorylates the nucleolar protein nopp44/46.trypanosoma brucei adapts to changing environments as it cycles through arrested and proliferating stages in the human and tsetse fly hosts. changes in protein tyrosine phosphorylation of several proteins, including nopp44/46, accompany t. brucei development. moreover, inactivation of t. brucei protein-tyrosine phosphatase 1 (tbptp1) triggers differentiation of bloodstream stumpy forms into tsetse procyclic forms through unknown downstream effects. here, we link these events by showing that nopp ...201020444707
sleeping sickness in southeastern uganda: a spatio-temporal analysis of disease risk, 1970-2003.sleeping sickness is a major threat to human health in sub-saharan africa. southeastern uganda has experienced a number of significant epidemics in the past 100 years, most recently from 1976 to 1989. recent and continued spread of the disease has highlighted gaps in the ability of current research to explain and predict the distribution of infection. vegetation cover and changes in vegetation may be important determinants of transmission and disease risk because of the habitat preferences of th ...201020482341
regulation of high-affinity iron acquisition homologues in the tsetse fly symbiont sodalis glossinidius.sodalis glossinidius is a facultative intracellular bacterium that is a secondary symbiont of the tsetse fly (diptera: glossinidae). since studies with other facultative intracellular bacteria have shown that high-affinity iron acquisition genes are upregulated in vivo, we investigated the regulation of several sodalis genes that encode putative iron acquisition systems. these genes, sg1538 (hemt) and sg1516 (sita), are homologous to genes encoding periplasmic heme and iron/manganese transporter ...201020494987
amplified fragment length polymorphism (aflp) analysis of closely related wild and captive tsetse fly (glossina morsitans morsitans) populations.abstract:201020504326
spatial clustering and associations of two savannah tsetse species, glossina morsitans submorsitans and glossina pallidipes (diptera: glossinidae), for guiding interventions in an adaptive cattle health management framework.the paper deals with tsetse (family glossinidae) control and aims at improving the methodology for precision targeting interventions in an adaptive pest management system. the spatio-temporal distribution of glossina morsitans submorsitans newstead, and glossina pallidipes austen, at ethiopia's keto pilot site, is analyzed with the spatial analysis by distance indices (sadie) methodology that focus on clustering and spatial associations between species and between sexes. both species displayed a ...201020504383
tsetse fly blood meal modification and trypanosome identification in two sleeping sickness foci in the forest of southern cameroon.the blood meal origins of 222 tsetse flies (213 glossina palpalis palpalis, 7 glossina pallicera pallicera, one glossina nigrofusca and one glossina caliginea) caught in 2008 in two human african trypanosomiasis foci (bipindi and campo) of south cameroon were investigated. 88.7% of tsetse flies blood meals were identified using the heteroduplex method and the origin of the remaining blood meals (11.3%) was identified by sequencing the cytochrome b gene. most of the meals were from humans (45.9%) ...201020541513
landmarks in the evolution of technologies for identifying trypanosomes in tsetse flies.understanding what the trypanosome pathogens are, their vectors and mode of transmission underpin efforts to control the disease they cause in both humans and livestock. the risk of transmission is estimated by determining what proportion of the vector population is carrying the infectious pathogens. this risk also depends on the infectivity of the trypanosomes to humans and livestock. most livestock pathogens are not infective to humans, whereas the two sub-species that infect humans also infec ...201020542733
a novel phosphatase cascade regulates differentiation in trypanosoma brucei via a glycosomal signaling pathway.in the mammalian bloodstream, the sleeping sickness parasite trypanosoma brucei is held poised for transmission by the activity of a tyrosine phosphatase, tbptp1. this prevents differentiation of the transmissible "stumpy forms" until entry into the tsetse fly, whereupon tbptp1 is inactivated and major changes in parasite physiology are initiated to allow colonization of the arthropod vector. using a substrate-trapping approach, we identified the downstream step in this developmental signaling p ...201020551176
bovine trypanosomosis and its vectors in two districts of bench maji zone, south western ethiopia.a cross-sectional study was carried out from november 2008 to february 2009 in guraferda and sheko districts of bench maji zone, south western ethiopia. the objective of the study was to determine the prevalence of bovine trypanosomosis and the density of its vectors. an overall prevalence of trypanosome infection in the study area was 4.4%. trypanosoma congolense (36.36%) was the dominant trypanosome species followed by trypanosoma vivax (18.18%) and trypanosoma brucei (9.09%). mean packed cell ...201020577803
mobile genetic element proliferation and gene inactivation impact over the genome structure and metabolic capabilities of sodalis glossinidius, the secondary endosymbiont of tsetse flies.genome reduction is a common evolutionary process in symbiotic and pathogenic bacteria. this process has been extensively characterized in bacterial endosymbionts of insects, where primary mutualistic bacteria represent the most extreme cases of genome reduction consequence of a massive process of gene inactivation and loss during their evolution from free-living ancestors. sodalis glossinidius, the secondary endosymbiont of tsetse flies, contains one of the few complete genomes of bacteria at t ...201020649993
a landscape and climate data logistic model of tsetse distribution in kenya.trypanosoma spp, biologically transmitted by the tsetse fly in africa, are a major cause of illness resulting in both high morbidity and mortality among humans, cattle, wild ungulates, and other species. however, tsetse fly distributions change rapidly due to environmental changes, and fine-scale distribution maps are few. due to data scarcity, most presence/absence estimates in kenya prior to 2000 are a combination of local reports, entomological knowledge, and topographic information. the avai ...201020676406
effects of ethidium (homidium bromide) on female reproductive performance of laboratory-reared tsetse flies, glossina morsitans morsitans westwood (diptera: glossinidae).ethidium (homidium bromide) is a trypanocide likely to be encountered as a violative residue in blood collected from abattoirs for feeding laboratory tsetse flies. we investigated its effect on female reproduction of glossina morsitans morsitans. one-milligram homidium per kilogram body weight was intra-muscularly administered to four steers and blood aseptically collected from them between 15 and 30 min post-treatment, analysed for homidium levels and processed for tsetse feeding. two hundred t ...201020678462
bottlenecks and the maintenance of minor genotypes during the life cycle of trypanosoma brucei.african trypanosomes are digenetic parasites that undergo part of their developmental cycle in mammals and part in tsetse flies. we established a novel technique to monitor the population dynamics of trypanosoma brucei throughout its life cycle while minimising the confounding factors of strain differences or variation in fitness. clones derived from a single trypanosome were tagged with short synthetic dna sequences in a non-transcribed region of the genome. infections were initiated with mixtu ...201020686656
proteomic analysis of glossina pallidipes salivary gland hypertrophy virus virions for immune intervention in tsetse fly colonies.many species of tsetse flies (diptera: glossinidae) can be infected by a virus that causes salivary gland hypertrophy (sgh). the genomes of viruses isolated from glossina pallidipes (gpsghv) and musca domestica (mdsghv) have recently been sequenced. tsetse flies with sgh have reduced fecundity and fertility which cause a serious problem for mass rearing in the frame of sterile insect technique (sit) programmes to control and eradicate tsetse populations in the wild. a potential intervention stra ...201020719992
discovery and verification of osteopontin and beta-2-microglobulin as promising markers for staging human african trypanosomiasis.human african trypanosomiasis, or sleeping sickness, is a parasitic disease endemic in sub-saharan africa, transmitted to humans through the bite of a tsetse fly. the first or hemolymphatic stage of the disease is associated with presence of parasites in the bloodstream, lymphatic system, and body tissues. if patients are left untreated, parasites cross the blood-brain barrier and invade the cerebrospinal fluid and the brain parenchyma, giving rise to the second or meningoencephalitic stage. sta ...201020724469
characterisations of odorant-binding proteins in the tsetse fly glossina morsitans morsitans.odorant-binding proteins (obps) play an important role in insect olfaction by mediating interactions between odorants and odorant receptors. we report for the first time 20 obp genes in the tsetse fly glossina morsitans morsitans. qrt-pcr revealed that 8 of these genes were highly transcribed in the antennae. the transcription of these genes in the antennae was significantly lower in males than in females and there was a clear correlation between obp gene transcription and feeding status. starva ...201020012146
evaluation of deltamethrin applications in the control of tsetse and trypanosomosis in the southern rift valley areas of ethiopia.a study aimed at evaluating the efficacy of deltamethrin (0.4% impregnated targets and 1% pour-on formulation) in controlling tsetse and trypanosomosis was carried out in two selected 10km x 10km universal transverse mercator grids of the southern tsetse eradication project (step) area in the southern rift valley of ethiopia. the grids selected were h3 (site i) and g5 (site ii) in two districts of the wolaita zone. the trial was underway from september 2003 to april 2004. the strategy followed t ...201020060647
diversity and spatial distribution of vectors and hosts of t. brucei gambiense in forest zones of, southern cameroon: epidemiological implications.host and vector distribution of trypanosoma brucei gambiense was studied in relation to habitat types and seasons. six (19.35%) of the 31 mammal species recorded in bipindi were reservoir hosts. cercopithecus nictitans was confined to the undisturbed forest and the low intensive shifting cultivation zones, while cephalophus monticola, cephalophus dorsalis, cricetomys gambianus, atherurus africanus and nandinia binotata occurred in all the habitat types. as for vectors of human african trypanosom ...201020067756
the transformer gene of ceratitis capitata: a paradigm for a conserved epigenetic master regulator of sex determination in insects.the transformer gene in ceratitis capitata (cctra(ep)) is the founding member of a family of related sr genes that appear to act as the master epigenetic switch in sex determination in insects. a functional protein seems to be produced only in individuals with a female xx karyotype where it is required to maintain the productive mode of expression through a positive feedback loop and to direct female development by instructing the downstream target genes accordingly. when zygotic activation of t ...201020890720
universal primers for rapid detection of hytrosaviruses.hytrosaviridae is a proposed virus family encompassing viruses that cause salivary gland hypertrophy (sgh) syndrome in infected insects and reduce the fertility in their dipteran insect hosts. they contain a large, double stranded dna genome of 120-190 kbp. to date, these viruses have been detected only in adult diptera. these include hytrosaviruses detected in various tsetse fly species (glossina spp.), the narcissus bulb fly merodon equestris and the house fly musca domestica. the limited numb ...201020923688
[eco-distribution and trypanosoma infection of glossina palpalis palpalis in the banco forest of and its relics, abidjan (côte d'ivoire)].in order to implement an anti-vector programme in the suburb of abidjan (côte d'ivoire), investigations were conducted to assess the tsetse fly densities as well as infection with trypanosomes. catches were carried out during the rainy season and dry season with vavoua traps laid during four consecutive days in different sites (banco forest, abidjan zoological park, area of the university of abobo-adjamé). one species of tsetse fly (glossina polpalis palpalis) and two species of trypanosomes (tr ...200920092060
the heart of darkness: growth and form of trypanosoma brucei in the tsetse fly.the first description of african trypanosomes was made over a century ago. the importance of the tsetse in transmission and cyclic development of trypanosomes was discovered soon afterwards, and has been the focus of numerous studies since. however, investigation of trypanosomes in tsetse flies requires high resource investment and unusual patience; hence, many facets of trypanosome biology in the tsetse remain to be characterised despite the long history of research. here, current knowledge and ...200919747880
alanine aminotransferase of trypanosoma brucei--a key role in proline metabolism in procyclic life forms.african trypanosomes possess high levels of alanine aminotransferase (ec 2.6.1.2), although the function of their activity remains enigmatic, especially in slender bloodstream forms where the metabolism of ketoacids does not occur. therefore, the gene for alanine aminotransferase enzyme in trypanosoma brucei (tbaat) was characterized and its function assessed using a combination of rna interference and gene knockout approaches. surprisingly, as much as 95% or more of the activity appears to be u ...200919895576
distribution and density of tsetse flies (glossinidae: diptera) at the game/people/livestock interface of the nkhotakota game reserve human sleeping sickness focus in malawi.in large parts sub-saharan africa, tsetse flies, the vectors of african human or animal trypanosomiasis, are, or will in the foreseeable future, be confined to protected areas such as game or national parks. challenge of people and livestock is likely to occur at the game/livestock/people interface of such infested areas. since tsetse control in protected areas is difficult, management of trypanosomiasis in people and/or livestock requires a good understanding of tsetse population dynamics along ...200919924484
maturation of a trypanosoma brucei infection to the infectious metacyclic stage is enhanced in nutritionally stressed tsetse flies.we report on the effect of tsetse fly starvation on the maturation of an established trypanosoma brucei brucei midgut infection, i.e., the development of procyclic infection into the infectious metacyclic parasites in the tsetse fly salivary glands. glossina morsitans morsitans flies were nutritionally stressed 10 d after the uptake of a t. b. brucei-infected bloodmeal by depriving these flies from feeding for seven consecutive days, whereas the control fly group (nonstarved group) continued to ...200919960695
tsetse and trypanosomosis in africa: the challenges, the opportunities.tsetse-fly and the disease it transmits, trypanosomosis, remain an enormous disease challenge in the 37 countries of sub-saharan africa where the impact continues to be manifest in disease burden, increased level of poverty and decreased agricultural productivity. the impact also extends over an estimated 10 million km2 (a third of the african continent) of land area, a third of which contains some well-watered part of the continent, thus denying humans and livestock of potentially rich arable a ...200919967926
transcriptome analysis of differentiating trypanosomes reveals the existence of multiple post-transcriptional regulons.trypanosome gene expression is regulated almost exclusively at the post-transcriptional level, with mrna degradation playing a decisive role. when trypanosomes are transferred from the blood of a mammal to the midgut of a tsetse fly, they transform to procyclic forms: gene expression is reprogrammed, changing the cell surface and switching the mode of energy metabolism. within the blood, trypanosomes can pre-adapt for tsetse transmission, becoming growth-arrested stumpy forms. we describe here t ...200919857263
the epidemiology of trypanosomiasis in rumphi district, malawi: a ten year retrospective study.human african trypanosomiasis (hat) is caused by two species of the tsetse fly vectored protozoan hemoflagellates belonging to trypanosma brucei, namely t.b gambiense which predominates in western africa and follows a chronic disease course and t.b rhodensiense which is more prevalent in southern and eastern africa, malawi included, and follows a more acute and aggressive disease course. previous studies in the democratic republic of congo, angola, uganda and sudan have demonstrated that the pre ...200919780474
first isolation of enterobacter, enterococcus, and acinetobacter spp. as inhabitants of the tsetse fly (glossina palpalis palpalis) midgut.this paper reports the first evidence of the presence of bacteria, other than the three previously described as symbionts, wigglesworthia glossinidia, wolbachia, and sodalis glossinidius, in the midgut of glossina palpalis palpalis, the tsetse fly, a vector of the chronic form of human african trypanosomiasis in sub-saharan african countries. based on the morphological, nutritional, physiological, and phylogenetic results, we identified enterobacter, enterococcus, and acinetobacter spp. as inhab ...200919800031
nutritional stress affects the tsetse fly's immune gene expression.tsetse-transmitted trypanosomiasis poses a serious threat to human and animal health in sub-saharan africa. the majority of tsetse flies (glossina spp.) in a natural population will not develop a mature infection of either trypanosoma congolense or trypanosoma brucei sp. because of refractoriness, a phenomenon that is affected by different factors, including the tsetse fly's immune defence. starvation of tsetse flies significantly increases their susceptibility to the establishment of a trypanos ...200919712150
monitoring the pleomorphism of trypanosoma brucei gambiense isolates in mouse: impact on its transmissibility to glossina palpalis gambiensis.substantial differences have been observed between the cyclical transmission of three trypanosoma brucei gambiense field isolates in glossina palpalis gambiensis (ravel et al., 2006). differences in the pleomorphism of these isolates in rodent used to provide the infective feed to glossina, could explain such results, since stumpy forms are preadapted for differentiation to procyclic forms when taken up in a tsetse bloodmeal. to assess this possibility, mice were immunosuppressed and inoculated ...200919720159
differential expression of a protease gene family in african trypanosomes.during their life cycle african trypanosomes must quickly adapt to the different environments of the tsetse fly midgut and the mammalian bloodstream by modulating expression of many of their genes. one group of these differentially expressed genes encodes different forms of a major surface protease. using a luciferase reporter gene transiently or permanently transfected into trypanosomes, we show here that the 3'-utrs of these protease genes are responsible for their differential expression. del ...200918848586
have tsetse flies disappeared from brazzaville town?from 1980 to 1985, the zoological park of brazzaville was the only tsetse resting site located in downtown which supplied others temporary sites. the last trapping survey carried out in this area in 1987 showed that there were no more tsetse flies. knowing that areas free of tsetse used to be reinvaded many years later, we have carried out an entomological survey in the area with the aim to verify what has happened more than twenty years later; given that suitable environmental conditions for gl ...200921532712
hearing in tsetse flies? morphology and mechanics of a putative auditory organ.tympanal hearing organs are widely used by insects to detect sound pressure. such ears are relatively uncommon in the order diptera, having only been reported in two families thus far. this study describes the general anatomical organization and experimentally examines the mechanical resonant properties of an unusual membranous structure situated on the ventral prothorax of the tsetse fly, glossina morsitans (diptera: glossinidae). anatomically, the prosternal membrane is backed by an air filled ...200918954491
prolonged gene knockdown in the tsetse fly glossina by feeding double stranded rna.reverse genetic studies based on rna interference (rnai) have revolutionized analysis of gene function in most insects. however the necessity of injecting double stranded rna (dsrna) inevitably compromises many investigations particularly those on immunity. additionally, injection of tsetse flies often causes significant mortality. we demonstrate, at transcript and protein level, that delivering dsrna in the bloodmeal to glossina morsitans morsitans is as effective as injection in knockdown of t ...200919016913
trypanosoma brucei brucei: effects of ferrous iron and heme on ecto-nucleoside triphosphate diphosphohydrolase activity.trypanosoma brucei brucei is the causative agent of animal african trypanosomiasis, also called nagana. procyclic vector form resides in the midgut of the tsetse fly, which feeds exclusively on blood. hemoglobin digestion occurs in the midgut resulting in an intense release of free heme. in the present study we show that the magnesium-dependent ecto-nucleoside triphosphate diphosphohydrolase (e-ntpdase) activity of procyclic t. brucei brucei is inhibited by ferrous iron and heme. the inhibition ...200919027737
establishment of an in vitro transgene expression system in epimastigotes of trypanosoma congolense.trypanosoma congolense epimastigote forms (emfs) adhere to the tsetse fly proboscis, proliferate, and differentiate into animal-infective metacyclic forms (mcfs). this differentiation step, called metacyclogenesis, is indispensable for the cyclical transmission of the parasite. although an in vitro metacyclogenesis culture system was established several decades ago, few genetic tools have been utilized to investigate the molecular mechanisms underlying t. congolense metacyclogenesis. this study ...200919135170
differential trypanosome surface coat regulation by a ccch protein that co-associates with procyclin mrna cis-elements.the genome of trypanosoma brucei is unusual in being regulated almost entirely at the post-transcriptional level. in terms of regulation, the best-studied genes are procyclins, which encode a family of major surface gpi-anchored glycoproteins (ep1, ep2, ep3, gpeet) that show differential expression in the parasite's tsetse-fly vector. although procyclin mrna cis-regulatory sequences have provided the paradigm for post-transcriptional control in kinetoplastid parasites, trans-acting regulators of ...200919247446
the population structure of glossina palpalis gambiensis from island and continental locations in coastal guinea.we undertook a population genetics analysis of the tsetse fly glossina palpalis gambiensis, a major vector of sleeping sickness in west africa, using microsatellite and mitochondrial dna markers. our aims were to estimate effective population size and the degree of isolation between coastal sites on the mainland of guinea and loos islands. the sampling locations encompassed dubréka, the area with the highest human african trypanosomosis (hat) prevalence in west africa, mangrove and savannah site ...200919290038
searching for novel cell cycle regulators in trypanosoma brucei with an rna interference screen.the protozoan parasite, trypanosoma brucei, is spread by the tsetse fly and causes human african trypanosomiasis. its cell cycle is complex and not fully understood at the molecular level. the t. brucei genome contains over 6000 protein coding genes with >50% having no predicted function. a small scale rna interference (rnai) screen was carried out in trypanosoma brucei to evaluate the prospects for identifying novel cycle regulators.200919309510
transcriptional profiling of cattle infected with trypanosoma congolense highlights gene expression signatures underlying trypanotolerance and trypanosusceptibility.african animal trypanosomiasis (aat) caused by tsetse fly-transmitted protozoa of the genus trypanosoma is a major constraint on livestock and agricultural production in africa and is among the top ten global cattle diseases impacting on the poor. here we show that a functional genomics approach can be used to identify temporal changes in host peripheral blood mononuclear cell (pbmc) gene expression due to disease progression. we also show that major gene expression differences exist between cat ...200919409086
a surface transporter family conveys the trypanosome differentiation signal.microbial pathogens use environmental cues to trigger the developmental events needed to infect mammalian hosts or transmit to disease vectors. the parasites causing african sleeping sickness respond to citrate or cis-aconitate (cca) to initiate life-cycle development when transmitted to their tsetse fly vector. this requires hypersensitization of the parasites to cca by exposure to low temperature, conditions encountered after tsetse fly feeding at dusk or dawn. here we identify a carboxylate-t ...200919444208
nutritional stress of adult female tsetse flies (diptera: glossinidae) affects the susceptibility of their offspring to trypanosomal infections.the epidemiology of tsetse-transmitted trypanosomiasis depends, among other factors, on the proportion of infected flies in a tsetse population. a wide range of intrinsic and extrinsic factors seem to determine the ability of a tsetse fly to become infected and to transmit the parasite. in this paper, we investigated the effect of nutritional stress of reproducing female glossina morsitans morsitans on the susceptibility of their offspring to trypanosomal infections. adult female flies that were ...200919445895
population sizes and dispersal pattern of tsetse flies: rolling on the river?the west african trypanosomoses are mostly transmitted by riverine species of tsetse fly. in this study, we estimate the dispersal and population size of tsetse populations located along the mouhoun river in burkina faso where tsetse habitats are experiencing increasing fragmentation caused by human encroachment. dispersal estimated through direct (mark and recapture) and indirect (genetic isolation by distance) methods appeared consistent with one another. in these fragmented landscapes, tsetse ...200919457176
hytrosaviridae: a proposal for classification and nomenclature of a new insect virus family.salivary gland hypertrophy viruses (sghvs) have been identified from different dipteran species, such as the tsetse fly glossina pallidipes (gpsghv), the housefly musca domestica (mdsghv) and the narcissus bulbfly merodon equestris (mesghv). these viruses share the following characteristics: (i) they produce non-occluded, enveloped, rod-shaped virions that measure 500-1,000 nm in length and 50-100 nm in diameter; (ii) they possess a large circular double-stranded dna (dsdna) genome ranging in si ...200919458899
experimental modifications imply a stimulatory function for male tsetse fly genitalia, supporting cryptic female choice theory.one of the most sweeping of all patterns in morphological evolution is that animal genitalia tend to diverge more rapidly than do other structures. abundant indirect evidence supports the cryptic female choice (cfc) explanation of this pattern, which supposes that male genitalia often function to court females during copulation; but direct experimental demonstrations of a stimulatory function have been lacking. in this study, we altered the form of two male genital structures that squeeze the fe ...200919467130
identification of a functional antigen5-related allergen in the saliva of a blood feeding insect, the tsetse fly.our previous screening of a glossina morsitans morsitans lamdagt11 salivary gland expression library with serum of a tsetse fly exposed rabbit identified a cdna encoding tsetse antigen5 (tag5, 28.9 kda), a homologue of antigen5 sting venom allergens. recombinant tag5 was produced in sf9 cells in order to assess its immunogenic properties in humans. plasma from a patient that previously exhibited anaphylactic reactions against tsetse fly bites contained circulating anti-tag5 and anti-saliva iges. ...200919507303
phenotypic plasticity of desiccation resistance in glossina puparia: are there ecotype constraints on acclimation responses?phenotypic plasticity allows organisms to cope with environmental variation and may aid in the evolution of novel traits. however, whether phenotypic plasticity is beneficial, or if acclimation responses might be constrained to particular ecotypes is generally poorly explored. here we test the beneficial acclimation hypothesis (bah) and its alternatives for desiccation resistance to atmospheric moisture in mesic- and xeric-adapted glossina species. highly significant interactions among acclimati ...200919522729
the impact of habitat fragmentation on tsetse abundance on the plateau of eastern zambia.tsetse-transmitted human or livestock trypanosomiasis is one of the major constraints to rural development in sub-saharan africa. the epidemiology of the disease is determined largely by tsetse fly density. a major factor, contributing to tsetse population density is the availability of suitable habitat. in large parts of africa, encroachment of people and their livestock resulted in a destruction and fragmentation of such suitable habitat. to determine the effect of habitat change on tsetse den ...200919523702
a model of pupal water loss in glossina.the results of a long-established investigation into pupal transpiration are used as a rudimentary data set. these data are then generalised to all temperatures and humidities by invoking the property of multiplicative separability, as well as by converting established relationships in terms of constant humidity at fixed temperature, to alternatives in terms of a calculated water loss. in this way a formulation which is a series of very simple, first order, ordinary differential equations is dev ...200919527739
adaptations in the glucose metabolism of procyclic trypanosoma brucei isolates from tsetse flies and during differentiation of bloodstream forms.procyclic forms of trypanosoma brucei isolated from the midguts of infected tsetse flies, or freshly transformed from a strain that is close to field isolates, do not use a complete krebs cycle. furthermore, short stumpy bloodstream forms produce acetate and are apparently metabolically preadapted to adequate functioning in the tsetse fly.200919542311
optimum land cover products for use in a glossina-morsitans habitat model of kenya.tsetse flies are the primary vector for african trypanosomiasis, a disease that affects both humans and livestock across the continent of africa. in 1973 tsetse flies were estimated to inhabit 22% of kenya; by 1996 that number had risen to roughly 34%. efforts to control the disease were hampered by a lack of information and costs associated with the identification of infested areas. given changing spatial and demographic factors, a model that can predict suitable tsetse fly habitat based on lan ...200919563674
the trypanosoma brucei flagellum: moving parasites in new directions.african trypanosomes are devastating human and animal pathogens. trypanosoma brucei rhodesiense and t. b. gambiense subspecies cause the fatal human disease known as african sleeping sickness. it is estimated that several hundred thousand new infections occur annually and the disease is fatal if untreated. t. brucei is transmitted by the tsetse fly and alternates between bloodstream-form and insect-form life cycle stages that are adapted to survive in the mammalian host and the insect vector, re ...200919575562
improving the cost-effectiveness of artificial visual baits for controlling the tsetse fly glossina fuscipes fuscipes.tsetse flies, which transmit sleeping sickness to humans and nagana to cattle, are commonly controlled by stationary artificial baits consisting of traps or insecticide-treated screens known as targets. in kenya the use of electrocuting sampling devices showed that the numbers of glossina fuscipes fuscipes (newstead) visiting a biconical trap were nearly double those visiting a black target of 100 cm x 100 cm. however, only 40% of the males and 21% of the females entered the trap, whereas 71% an ...200919582138
[distribution and ecology of the savannah human african trypanosomiasis vectors in disturbed forest zone in south cameroon: about case in the doumé forest].vector control through trapping in the foci of humid forest areas is rather difficult because of the wide spreading of tsetse flies and transmission sites of human african trypanosomiasis. in fact, traps should be a priori set up everywhere to stop the transmission. the identification of the disease transmission sites enables efficient trapping through localisation of dangerous tsetse flies habitats needing vector control measures. the study of adult tsetse flies and teneral tsetse flies spatial ...200919583032
experimental demonstration of possible cryptic female choice on male tsetse fly genitalia.a possible explanation for one of the most general trends in animal evolution - rapid divergent evolution of animal genitalia - is that male genitalia are used as courtship devices that influence cryptic female choice. but experimental demonstrations of stimulatory effects of male genitalia on female reproductive processes have generally been lacking. previous studies of female reproductive physiology in the tsetse fly glossina morsitans suggested that stimulation during copulation triggers ovul ...200919607835
evidence for a discrete evolutionary lineage within equatorial guinea suggests that the tsetse fly glossina palpalis palpalis exists as a species complex.tsetse flies of the palpalis group are major vectors of human african trypanosomiasis in africa. accurate knowledge of species identity is essential for vector control. here, we combine ribosomal internal transcribed spacer 1 (its1), mitochondrial cytochrome oxidase 1 (coi) and microsatellites to determine the population structure and phylogenetic relations of glossina p. palpalis in equatorial guinea. co1 sequence data suggest that g. p. palpalis in equatorial guinea is a distinct subspecies fr ...200919619197
olfactory and behavioural responses of tsetse flies, glossina spp., to rumen metabolites.herbivores provide tsetse flies with a blood meal, and both wild and domesticated ruminants dominate as hosts. as volatile metabolites from the rumen are regularly eructed with rumen gas, these products could serve tsetse flies during host searching. to test this, we first established that the odour of rumen fluid is attractive to hungry glossina pallidipes in a wind tunnel. we then made antennogram recordings from three tsetse species (g. pallidipes morsitans group, g. fuscipes palpalis group a ...200919626328
trypanosoma brucei amp-activated kinase subunit homologs influence surface molecule expression.the african trypanosome, trypanosoma brucei, can gauge its environment by sensing nutrient availability. for example, procyclic form (pf) trypanosomes monitor changes in glucose levels to regulate surface molecule expression, which is important for survival in the tsetse fly vector. the molecular connection between glycolysis and surface molecule expression is unknown. here we partially characterize t. brucei homologs of the beta and gamma subunits of the amp-activated protein kinase (ampk), and ...200919647733
the use of yellow fluorescent hybrids to indicate mating in trypanosoma brucei.abstract:200818298832
biostraticola tofi gen. nov., spec. nov., a novel member of the family enterobacteriaceae.bacterial strain bf36t, isolated from the biofilm of a tufa deposit in a hard water rivulet, was characterized by a polyphasic taxonomic approach. cells of these organisms were gram-negative, motile, nonpigmented, rod-shaped, non-endospore-forming, and facultatively anaerobic. cells, organized in loose consortia, were coated by a massive slime layer. phylogenetic analyses using 16s rrna gene sequences showed that strain bf36t was a member of the family enterobacteriaceae, class gammaproteobacter ...200818324435
from ubombo to mkhuzi: disease, colonial science, and the control of nagana (livestock trypanosomosis) in zululand, south africa, c. 1894-1953.this article looks at the scientific studies and debates that surrounded the control of nagana (trypanosomosis in livestock) in zululand, south africa, from the late nineteenth century until the 1950s. by 1953 the disease appeared to be contained following the use of ddt to exterminate the tsetse fly that spread the infection from immune wildlife to susceptible livestock. it argues that south africa made an important contribution to western knowledge about trypanosomosis in terms of its etiology ...200818326887
infections with immunogenic trypanosomes reduce tsetse reproductive fitness: potential impact of different parasite strains on vector population structure.the parasite trypanosoma brucei rhodesiense and its insect vector glossina morsitans morsitans were used to evaluate the effect of parasite clearance (resistance) as well as the cost of midgut infections on tsetse host fitness. tsetse flies are viviparous and have a low reproductive capacity, giving birth to only 6-8 progeny during their lifetime. thus, small perturbations to their reproductive fitness can have a major impact on population densities. we measured the fecundity (number of larval p ...200818335067
turnover of glycosomes during life-cycle differentiation of trypanosoma brucei.protozoan kinetoplastida, a group that comprises the pathogenic trypanosoma brucei, compartmentalize several metabolic systems such as the major part of the glycolytic pathway, in multiple peroxisome-like organelles, designated glycosomes. trypanosomes have a complicated life cycle, involving two major, distinct stages living in the mammalian bloodstream and several stages inhabiting different body parts of the tsetse fly. previous studies on non-differentiating trypanosomes have shown that the ...200818365344
n-acetyl d-glucosamine stimulates growth in procyclic forms of trypanosoma brucei by inducing a metabolic shift.summarythe lectin-inhibitory sugars d-glucosamine (glcn) and n-acetyl d-glucosamine (glcnac) are known to enhance susceptibility of the tsetse fly vector to infection with trypanosoma brucei. glcnac also stimulates trypanosome growth in vitro in the absence of any factor derived from the fly. here, we show that glcnac cannot be used as a direct energy source, nor is it internalized by trypanosomes. it does, however, inhibit glucose uptake by binding to the hexose transporter. deprivation of d-gl ...200818371239
seasonal distribution and abundance of tsetse flies (glossina spp.) in the faro and deo division of the adamaoua plateau in cameroon.ten years after the large-scale tsetse control campaigns in the important cattle rearing areas of the faro and deo division of the adamaoua plateau in cameroon, the seasonal distribution and abundance of tsetse flies (glossina spp.) were determined. during a period of 12 consecutive months (january-december 2005), the tsetse population was monitored along four trap transects consisting of a total of 32 traps and two flyround transects traversing the study area, which comprised the tsetse-infeste ...200818380651
detection of trypanosoma brucei in field-captured tsetse flies and identification of host species fed on by the infected flies.the prevalence of trypanosome infections in tsetse flies in the chiawa area of lower zambezi in zambia, with endemic trypanosomosis, was determined by a polymerase chain reaction (pcr) method that allowed the detection of trypanosome dna and determination of the type of animal host fed on by the tsetse fly glossina pallidipes, using tsetse-derived dna extracts as templates. ninety g. pallidipes (82 females and 8 males; 18.3%) of the 492 flies captured by baited biconical traps tested positive fo ...200818399780
simple tools for assembling and searching high-density picolitre pyrophosphate sequence data.abstract:200818423012
health management of horses under high challenge from trypanosomes: a case study from serengeti, tanzania.horses kept for recreational riding purposes by a wildlife tourism company in a heavily tsetse fly-infested region of north-western tanzania were systematically monitored to investigate the occurrence, presentation and management of tsetse-transmitted trypanosomosis. during a 23-month period, 18 clinical cases were diagnosed (trypanosoma brucei or trypanosoma congolense were identified) and treated and trypanosomes were implicated of involvement in four deaths. pyrexia consistently aided early d ...200818450381
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