Publications

antioxidant gene expression in the blood-feeding fly glossina morsitans morsitans.	we report the characterization of 11 antioxidant genes from the tsetse fly glossina m. morsitans. through similarity searches which detected homology we suggest that these genes consist of two superoxide dismutases (one with a putative signal peptide), three thioredoxin peroxidases (one with a putative signal peptide), three peroxiredoxins, one further signal peptide-containing peroxidase with its closest similarity to a glutathione peroxidase, one catalase and one thioredoxin reductase. we desc ...	2005	16164604
macrogeographic population structure of the tsetse fly, glossina pallidipes (diptera: glossinidae).	tsetse flies are confined to sub-saharan africa where they occupy discontinuous habitats. in anticipation of area-wide control programmes, estimates of gene flow among tsetse populations are necessary. genetic diversities were partitioned at eight microsatellite loci and five mitochondrial loci in 21 glossina pallidipes austin populations. at microsatellite loci, nei's unbiased gene diversity averaged over loci was 0.659 and the total number of alleles was 214, only four of which were shared amo ...	2005	16197564
an antimicrobial peptide with trypanocidal activity characterized from glossina morsitans morsitans.	tsetse flies (diptera:glossinidae) are vectors of african trypanosomes, the protozoan agents of devastating diseases in humans and animals. prior studies in trypanosome infected glossina morsitans morsitans have shown induced expression and synthesis of several antimicrobial peptides in fat body tissue. here, we have expressed one of these peptides, attacin (gmatta1) in drosophila (s2) cells in vitro. we show that the purified recombinant protein (recgmatta1) has strong antimicrobial activity ag ...	2005	15681221
tetracycline induction of gene expression in trypanosoma brucei within the tsetse fly vector.		2005	15760664
cloning and expression of a fat body-specific chitinase cdna from the spider, araneus ventricosus.	a fat body-specific chitinase cdna was cloned from the spider, araneus ventricosus. the cdna encoding a. ventricosus chitinase (avchit1) is 1515 bp long with an open reading frame (orf) of 431 amino acid residues. avchit1 possesses the chitinase family 18 active site signature and one n-glycosylation site. the deduced amino acid sequence of avchit1 cdna showed 43% identity to both glossina morsitans morsitans chitinase and a human chitotriosidase, and 30-40% to some insect chitinases which lack ...	2005	15694591
molecular cloning and characterization of a peroxiredoxin gene from the mole cricket, gryllotalpa orientalis.	we report the cloning, expression and characterization of a cdna encoding the antioxidant enzyme peroxiredoxin (prx) from the mole cricket, gryllotalpa orientalis. the g. orientalis prx (goprx) cdna contains an open reading frame of 660 bp encoding 220 amino acid residues and possesses one cysteine residue that is characteristic of the 1-cys subgroup of the peroxiredoxin family. the deduced amino acid sequence of the goprx cdna showed 69% identity to drosophila melanogaster dpx-2540, 50% to d. m ...	2005	15763513
increased expression of unusual ep repeat-containing proteins in the midgut of the tsetse fly (glossina) after bacterial challenge.	proteins containing a glutamic acid-proline (ep) repeat epitope were immunologically detected in midguts from eight species of glossina (tsetse flies). the molecular masses of the tsetse ep proteins differed among species groups. the amino acid sequence of one of these proteins, from glossina palpalis palpalis, was determined and compared to the sequence of a homologue, the tsetse midgut ep protein of glossina m. morsitans. the extended ep repeat domains comprised between 36% (g. m. morsitans) a ...	2005	15804575
african trypanosomiasis: changing epidemiology and consequences.	human african trypanosomiasis has re-emerged as a serious public health threat after near-elimination because of diminished investment in previously successful control programs. the continued, occasional importation of african trypanosomiasis to the united states can be expected as tourists and immigrants travel from high-risk areas. no vaccine or chemoprophylaxis is available for this disease, and travelers to affected areas should be counseled on tsetse fly avoidance. new diagnostic and stagin ...	2005	15610672
identification of midgut proteins that are differentially expressed in trypanosome-susceptible and normal tsetse flies (glossina morsitans morsitans).	molecules in the midgut of tsetse flies (diptera: glossinidiae) are thought to play important roles in the life cycle of african trypanosomes by influencing initial parasite establishment and subsequent differentiation events that ultimately lead to maturation of mammal-infective trypanosomes. the molecular composition of the tsetse midgut is, therefore, of critical importance to disease transmission by these medically important vectors. in this study we compared protein expression profiles of m ...	2005	15804576
sex separation of tsetse fly pupae using near-infrared spectroscopy.	implementation of the sterile insect technique for tsetse (glossina spp.) requires that only sterile male insects be released; thus, at some stage of the fly production process the females have to be removed. a further constraint in the use of the sterile insect technique for tsetse is that the females are needed for colony production and hence, a non-destructive method of sex separation is required. in most tsetse sterile insect technique programmes thus far, females have been eliminated from t ...	2005	15960879
expression of procyclin mrnas during cyclical transmission of trypanosoma brucei.	trypanosoma brucei, the parasite causing human sleeping sickness, relies on the tsetse fly for its transmission. in the insect, ep and gpeet procyclins are the major surface glycoproteins of procyclic (midgut) forms of the parasite, with gpeet predominating in the early procyclic form and two isoforms of ep in the late procyclic form. ep procyclins were previously detected on salivary gland trypanosomes, presumably epimastigotes, by immunoelectron microscopy. however, no procyclins could be dete ...	2005	16276404
disruption of the developmental programme of trypanosoma brucei by genetic ablation of tbzfp1, a differentiation-enriched ccch protein.	the regulation of differentiation is particularly important in microbial eukaryotes that inhabit multiple environments. the parasite trypanosoma brucei is an extreme example of this, requiring exquisite gene regulation during transmission from mammals to the tsetse fly vector. unusually, trypanosomes rely almost exclusively on post-transcriptional mechanisms for regulated gene expression. hence, rna binding proteins are potentially of great significance in controlling stage-regulated processes. ...	2005	16045615
spontaneous cure of domestic pigs experimentally infected by trypanosoma brucei gambiense. implications for the control of sleeping sickness.	the existence of a pig reservoir for human african trypanosomosis (hat) due to trypanosoma brucei gambiense complicates the fight against this disease. this study, reports results obtained from pigs, which were inoculated with the blood of a person, suffering from hat in cameroon. the pigs were reared and kept in the shelter from all contact with glossina, and monitored for 188 days. the seroconversion was checked by agglutination assays for trypanosomosis (catt 1.3 and latex/t.b.gambiense). the ...	2005	16076528
immunization of rabbits with glossina pallidipes tsetse fly midgut proteins: effects on the fly and trypanosome transmission.	proteins isolated from the midgut of glossina pallidipes were used to immunize rabbits and their efficacy as vaccine candidate(s) against the fly, and their potential to block transmission of trypanosoma brucei rhodesiense assessed. two fractions, detergent (det) and aqueous (aq) fractions were separated using a non-ionic detergent (triton x-114) and a series of bioassay experiments carried out using serum obtained from rabbits immunized with either of the two fractions. the mortality rates of t ...	2005	15893620
interactions among multiple genomes: tsetse, its symbionts and trypanosomes.	insect-borne diseases exact a high public health burden and have a devastating impact on livestock and agriculture. to date, control has proved to be exceedingly difficult. one such disease that has plagued sub-saharan africa is caused by the protozoan african trypanosomes (trypanosoma species) and transmitted by tsetse flies (diptera: glossinidae). this presentation describes the biology of the tsetse fly and its interactions with trypanosomes as well as its symbionts. tsetse can harbor up to t ...	2005	15894186
using bacteria to express and display anti-parasite molecules in mosquitoes: current and future strategies.	vector-borne diseases impose enormous health and economical burdens throughout the world. unfortunately, as insecticide and drug resistance spread, these burdens will increase unless new control measures are developed. genetically modifying vectors to be incapable of transmitting parasites is one possible control strategy and much progress has been made towards this goal. numerous effector molecules have been identified that interfere with parasite development in its insect vectors, and techniqu ...	2005	15894187
temperature-dependence of metabolic rate in glossina morsitans morsitans (diptera, glossinidae) does not vary with gender, age, feeding, pregnancy or acclimation.	while variation in metabolic rate at a single temperature can occur for a variety of reasons and the effect of temperature is well established in insects, within-generation variation of metabolic rate-temperature relationships has been relatively poorly explored. in this study, we investigate the effects of gender, age, feeding and pregnancy, as well as three acclimation temperatures (19, 24, 29 degrees c), on standard metabolic rate and its temperature-dependence within post-developmental (i.e. ...	2005	15927198
sodalis glossinidius (enterobacteriaceae) and vectorial competence of glossina palpalis gambiensis and glossina morsitans morsitans for trypanosoma congolense savannah type.	sodalis glossinidius is an endosymbiont of glossina palpalis gambiensis and glossina morsitans morsitans, the vectors of trypanosoma congolense. the presence of the symbiont was investigated by pcr in trypanosoma congolense savannah type-infected and noninfected midguts of both fly species, and into the probosces of flies displaying either mature or immature infection, to investigate possible correlation with the vectorial competence of tsetse flies. sodalis glossinidius was detected in all midg ...	2005	15942697
development of an adaptive tsetse population management scheme for the luke community, ethiopia.	since 1996, tsetse (glossina spp.) control operations, using odor-baited traps, have been carried out in the luke area of gurage zone, southwestern ethiopia. glossina morsitans submorsitans newstead was identified as the dominant species in the area, but the presence of glossina fuscipes newstead and glossina pallidipes austen also was recorded. here, we refer to the combined number of these three species and report the work undertaken from october 2002 to october 2004 to render the control syst ...	2005	16465742
experimental trypanosomiasis in yankasa ewes: the body weight response.	sleeping sickness (african trypanosomasis) is an anthropozoonosis transmitted primarily by the tsetse fly. it is associated with a host of clinical indices ranging from fever, aneamia and anorexia to reproductive failures in man and his domestic animals. the main objective of this study is to appraise the responsiveness of the body weight as a clinical indicator of sleeping sickness in experimentally infected yankasa ewes. twelve mature yankasa sheep (6 infected and 6 control ewes) were used in ...	2004	15977439
expression of a major surface protein of trypanosoma brucei insect forms is controlled by the activity of mitochondrial enzymes.	in cycling between the mammalian host and the tsetse fly vector, trypanosomes undergo major changes in energy metabolism and surface coat composition. early procyclic (insect) forms in the tsetse fly midgut are coated by glycoproteins known as ep and gpeet procyclins. ep expression continues in late procyclic forms, whereas gpeet is down-regulated. in culture, expression of gpeet is modulated by glycerol or glucose. here, we demonstrate that a glycerol-responsive element of 25 nucleotides within ...	2004	15201340
african labs win major role in tsetse-fly genome project.		2004	14749791
cold shock and regulation of surface protein trafficking convey sensitization to inducers of stage differentiation in trypanosoma brucei.	transmission of a protozoan parasite from a vertebrate to invertebrate host is accompanied by cellular differentiation. the signals from the environment that trigger the process are poorly understood. the model parasite trypanosoma brucei proliferates in the mammalian bloodstream and in the tsetse fly. on ingestion by the tsetse, the trypanosome undergoes a rapid differentiation that is marked by replacement of the variant surface glycoprotein (vsg) coat with gpi-anchored ep and gpeet procyclins ...	2004	15545633
african trypanosome interactions with an in vitro model of the human blood-brain barrier.	the neurological manifestations of sleeping sickness in man are attributed to the penetration of the blood-brain barrier (bbb) and invasion of the central nervous system by trypanosoma brucei gambiense and trypanosoma brucei rhodesiense. however, how african trypanosomes cross the bbb remains an unresolved issue. we have examined the traversal of african trypanosomes across the human bbb using an in vitro bbb model system constructed of human brain microvascular endothelial cells (bmecs) grown o ...	2004	15562595
knowledge and attitudes of cattle owners regarding trypanosomosis control in tsetse-infested areas of uganda.	a pilot survey using a structured questionnaire was conducted in tororo and busia districts of uganda on the knowledge and attitudes of cattle owners regarding tsetse fly and trypanosomosis control, in order to understand factors that hindered their full participation. a total of 81 cattle owners was randomly selected and interviewed, of which 92.5% were aware of tsetse flies and trypanosomosis and 87.6% recognised animal trypanosomosis as a problem in the area. most cattle owners were aware of ...	2004	15830601
tsetseep, a gut protein from the tsetse glossina morsitans, is related to a major surface glycoprotein of trypanosomes transmitted by the fly and to the products of a drosophila gene family.	african trypanosomes live in the lumen of the gut of tsetse (glossina) and may have to face an immune response. as yet, it is unclear whether they are sensitive to antimicrobial peptides in vivo, but for some years there has been indirect evidence that one or more lectins can influence the infection. we have purified a protein complex from midgut extracts that, by sds-page, is a doublet of 37 and 38 kda in a ratio of 3:1. through prediction from corresponding cdna clones, the full-length protein ...	2004	15522612
tsetse flies are attracted to the invasive plant lantana camara.	in tsetse both sexes feed exclusively on the blood of vertebrates for a few minutes every 2-3 days. tsetse flies seek cover from high temperatures to conserve energy and plants provide shelter for tsetse in all the biotopes they occupy. recently, tsetse have taken cover in plantations and under the invasive bush lantana camara that has invaded large areas of the tsetse fly belt of africa. flies from such refugia are implicated in sleeping sickness epidemics. in a wind tunnel we show that both fo ...	2004	15037092
the trypanosoma brucei cyclin, cyc2, is required for cell cycle progression through g1 phase and for maintenance of procyclic form cell morphology.	cyc2 is an essential pho80-like cyclin that forms a complex with the cdc2-related kinase crk3 in trypanosoma brucei. in both procyclic and bloodstream form t. brucei, knock-down of cyc2 by rna interference (rnai) led to an accumulation of cells in g(1) phase. additionally, in procyclic cells, but not in bloodstream form cells, cyc2 rnai induced a specific cell elongation at the posterior end. the g(1) block, as well as the posterior end elongation in the procyclic form, was irreversible once est ...	2004	15039435
comparison of the infection rate of tsetse, glossina morsitans morsitans, fed in vitro or in vivo.	studies were made of infection rates of trypanosomes in the tsetse fly glossina morsitans morsitans westwood (diptera: glossinidae) when maintained in vivo (rabbits) or in vitro on high quality, gamma-irradiated, sterile defibrinated bovine blood, obtained from the entomology unit of the international atomic energy agency (iaea). for both trypanosoma congolense broden and t. b. brucei plimmer & bradford, in vitro maintenance significantly reduced the proportion of flies that developed mature met ...	2004	15009448
human african trypanosomiasis: clinical presentation and immune response.	human african trypanosomiasis or sleeping sickness is caused by infection with two subspecies of the tsetse-fly-vectored haemoflagellate parasite trypanosoma brucei. historically, epidemic sleeping sickness has caused massive loss of life, and related animal diseases have had a crucial impact on development in sub-saharan africa. after a period of moderately successful control during the mid-part of the 20th century, sleeping sickness incidence is currently rising, and control is hampered by a c ...	2004	15771682
inhibition of the dna amplification of trypanosomes present in tsetse flies midguts: implications for the identification of trypanosome species in wild tsetse flies.	the present study was carried out in order to investigate if there was really a failure of pcr in identifying parasitologically positive tsetse flies in the field. tsetse flies (glossina palpalis gambiensis and glossina morsitans morsitans) were therefore experimentally infected with two different species of trypanosoma (trypanosoma brucei gambiense or trypanosoma congolense). a total of 152 tsetse flies were dissected, and organs of each fly (midgut, proboscis or salivary glands) were examined. ...	2004	15071836
the transmission of mixed trypanosoma brucei brucei/t. congolense infections by tsetse (glossina morsitans morsitans).	laboratory experiments and field observations clearly show that tsetse flies can be carriers of mixed trypanosome infections. question remains how easy it is for the tsetse fly to acquire such a mixed infection during the first bloodmeal. this is of particular importance in the epidemiology of trypanosoma brucei s.l., often a cryptic infection and difficult to transmit to non-teneral tsetse flies. to determine the transmission rate of t. brucei as part of a mixed infection, teneral glossina mors ...	2004	14746974
characterization of a digestive carboxypeptidase from the insect pest corn earworm (helicoverpa armigera) with novel specificity towards c-terminal glutamate residues.	carboxypeptidases were purified from guts of larvae of corn earworm (helicoverpa armigera), a lepidopteran crop pest, by affinity chromatography on immobilized potato carboxypeptidase inhibitor, and characterized by n-terminal sequencing. a larval gut cdna library was screened using probes based on these protein sequences. cdna haca42 encoded a carboxypeptidase with sequence similarity to enzymes of clan mc [barrett, a. j., rawlings, n. d. & woessner, j. f. (1998) handbook of proteolytic enzymes ...	2004	15128309
metabolic rate variation in glossina pallidipes (diptera: glossinidae): gender, ageing and repeatability.	despite the importance of metabolic rate in determining flight time of tsetse and in mediating the influence of abiotic variables on life history parameters (and hence abundance and distribution), metabolic rate measurements and their repeatability have not been widely assessed in these flies. we investigate age-related changes in standard metabolic rate (smr) and its repeatability, using flow-through respirometry, for a variety of feeding, gender and pregnancy classes during early adult develop ...	2004	15121455
history of sleeping sickness (african trypanosomiasis).	infections with subspecies of the protozoan parasite trypanosoma brucei cause important wasting diseases in africa (nagana in cattle and sleeping sickness in humans). these diseases were little known until the end of the nineteenth century when serious epidemics of nagana were reported and raised concern among the colonial powers. the early history of sleeping sickness revolves around the discovery of the causative organism, its mode of transmission,and its life cycle in the tsetse fly. the hist ...	2004	15145378
surface sialic acids taken from the host allow trypanosome survival in tsetse fly vectors.	the african trypanosome trypanosoma brucei, which causes sleeping sickness in humans and nagana disease in livestock, is spread via blood-sucking tsetse flies. in the fly's intestine, the trypanosomes survive digestive and trypanocidal environments, proliferate, and translocate into the salivary gland, where they become infectious to the next mammalian host. here, we show that for successful survival in tsetse flies, the trypanosomes use trans-sialidase to transfer sialic acids that they cannot ...	2004	15136592
a novel purine nucleoside transporter whose expression is up-regulated in the short stumpy form of the trypanosoma brucei life cycle.	purine nucleoside and nucleobase transporters play a vital role in the metabolism and survival of trypanosoma brucei because this parasitic protozoan is unable to synthesize purines de novo and thus must acquire preformed purines from its hosts. these parasites express a variety of nucleoside and nucleobase permeases with diverse substrate specificities and distinct patterns of expression during the trypanosome life cycle. we report here that expression of the newly characterized t. brucei nucle ...	2004	15478805
admixture and diversity in west african cattle populations.	we present a population genetic analysis of microsatellite variation in 16 west african cattle populations. west africa represents a unique juxtaposition of different climatic and ecological zones in a relatively small geographical area. while more humid coastal regions are inhabited by the tsetse fly, a vector which spreads trypanosomiasis among cattle, the disease is not transmitted in the drier areas outside this zone. this is the most thorough study of genetic diversity in cattle within this ...	2004	15488005
control of human african trypanosomiasis: trap and odour preference of tsetse flies (glossina morsitans submorsitans) in the upper didessa river valley of ethiopia.	ethiopia is one of the endemic countries for human african trypanosomiasis (hat) as over 100,000 people are at risk of having the disease. the control of hat using odour preference of tsetse flies (glossina morsitans submorsitans) was studied in upper didessa river valley of ethiopia. no information exists on the effectiveness of attractants for these species of tsetse flies in ethiopia. three attractants and their combinations namely: acetone, octenol, cow urine, acetone + octenol, acetone + oc ...	2004	15189461
a conserved domain of alkaline phosphatase expression in the malpighian tubules of dipteran insects.	malpighian (renal) tubules are key components of the insect osmoregulatory system and show correspondingly great diversity in both number and length. recently, the organisation of the drosophila melanogaster tubule has been elucidated by enhancer trapping, and an array for functional properties has been shown to align with the functional domains. in drosophila, there is a lower tubule domain, which coincides with expression of alkaline phosphatase and delineates the absorptive region of the tubu ...	2004	15326206
conservation of capa peptide-induced nitric oxide signalling in diptera.	in d. melanogaster malpighian (renal) tubules, the capa peptides stimulate production of nitric oxide (no) and guanosine 3', 5'-cyclic monophosphate (cgmp), resulting in increased fluid transport. the roles of no synthase (nos), no and cgmp in capa peptide signalling were tested in several other insect species of medical relevance within the diptera (aedes aegypti, anopheles stephensi and glossina morsitans) and in one orthopteran out-group, schistocerca gregaria. nos immunoreactivity was detect ...	2004	15498959
the macrocyclic lactone "spinosad," a promising insecticide for tsetse fly control.	the susceptibility of tsetse flies (diptera: glossinidae), glossina palpalis gambiensis (vanderplank), and g. m. morsitans (westwood) to topically applied spinosad, a mixture of insecticidal molecules from the actinomycete saccharopolyspora spinosa, is almost as high as to deltamethrin. however, susceptibility to spinosad does not differ significantly between teneral and gravid flies, contrary to deltamethrin. spinosad might be a promising candidate for future tsetse control by the sequential ae ...	2004	15535607
cloning and expression of the yolk protein of the tsetse fly glossina morsitans morsitans.	two major families of nutritional proteins exist in insects, namely the vitellogenins and the yolk proteins. while in other insects only vitellogenins are found, cyclorraphan flies only contain yolk proteins. possible sites of yolk protein synthesis are the fat body and the follicle cells surrounding the oocyte. we report the cloning of the yolk protein of the tsetse fly glossina morsitans morsitans, a species with adenotrophic viviparity. the tsetse fly yolk protein could be aligned with other ...	2004	15544941
proventriculus (cardia) plays a crucial role in immunity in tsetse fly (diptera: glossinidiae).	fat body and hemocytes play a central role in cellular and humoral responses for systemic infections in invertebrates, similar to the mammalian liver and blood cells. epithelial surfaces, in particular the midgut, participate in the initial local immune responses in order to aid in the generation of the terminal cytotoxic molecules that mediate non-self recognition. here, we describe for the first time the immune responses of a cluster of cells at the foregut/midgut junction--known as proventric ...	2003	14563366
local skin reaction (chancre) induced following inoculation of metacyclic trypanosomes in cattle by tsetse flies is dependent on cd4 t lymphocytes.	the first visible response in livestock to the bite of a trypanosome-infected tsetse fly is the formation of a localized skin reaction, also known as a chancre. this is an inflammatory response in the skin associated with swelling and an influx of cells. it is thought to be associated with an acquired immune response to the injected metacyclic trypanosomes. in this study, we examined the role of t lymphocytes in the development of the inflammatory response, by depleting cattle of t cell subpopul ...	2003	14651588
responses of glossina morsitans morsitans to blends of electroantennographically active compounds in the odors of its preferred (buffalo and ox) and nonpreferred (waterbuck) hosts.	in a previous study, comparison of the behavior of teneral glossina morsitans morsitans on waterbuck, kobus defassa (a refractory host), and on two preferred hosts, buffalo, syncerus caffer, and ox, bos indicus, suggested the presence of allomones in the waterbuck odor. examination of the volatile odors by coupled gas chromatography-electroantennographic detection showed that the antennal receptors of the flies detected constituents common to the three bovids (phenols and aldehydes), as well as ...	2003	14682515
the development of trypanosoma brucei within the tsetse fly midgut observed using green fluorescent trypanosomes.	background: the protozoan pathogen, trypanosoma brucei, undergoes complex cycles of differentiation and multiplication in its vector, the tsetse fly, genus glossina. flies are refractory to infection and resistance mechanisms operate at a number of levels and timepoints. here we have used highly conspicuous green fluorescent trypanosomes to study the early events in establishment of infection in the fly midgut. results: less than 10% of the bloodstream form trypanosomes in the infected feed diff ...	2003	12769824
cleavage of trypanosome surface glycoproteins by alkaline trypsin-like enzyme(s) in the midgut of glossina morsitans.	ep and gpeet procyclin, the major surface glycoproteins of procyclic forms of trypanosoma brucei, are truncated by proteases in the midgut of the tsetse fly glossina morsitans morsitans. we show that soluble extracts from the midguts of teneral flies contain trypsin-like enzymes that cleave the n-terminal domains from living culture-derived parasites. the same extract shows little activity against a variant surface glycoprotein on living bloodstream form t. brucei (mitat 1.2) and none against gl ...	2003	14527515
surface coat remodeling during differentiation of trypanosoma brucei.	african trypanosomes (trypanosoma brucei) are digenetic parasites whose lifecycle alternates between the mammalian bloodstream and the midgut of the tsetse fly vector. in mammals, proliferating long slender parasites transform into non-diving short stumpy forms, which differentiate into procyclic forms when ingested by the tsetse fly. a hallmark of differentiation is the replacement of the bloodstream stage surface coat composed of variant surface glycoprotein (vsg) with a new coat composed of p ...	2003	12716904
adult midgut expressed sequence tags from the tsetse fly glossina morsitans morsitans and expression analysis of putative immune response genes.	tsetse flies transmit african trypanosomiasis leading to half a million cases annually. trypanosomiasis in animals (nagana) remains a massive brake on african agricultural development. while trypanosome biology is widely studied, knowledge of tsetse flies is very limited, particularly at the molecular level. this is a serious impediment to investigations of tsetse-trypanosome interactions. we have undertaken an expressed sequence tag (est) project on the adult tsetse midgut, the major organ syst ...	2003	14519198
tsetse fly population genetics: an indirect approach to dispersal.	tsetse populations are distributed discontinuously, particularly the morsitans group. dispersal among diverse populations cannot easily be measured directly because the geographical distances between them can be too great to have a reasonable expectation of recapturing experimentally released flies. moreover, reproductive success of widely dispersed flies might be poor. the question of dispersal rates in tsetse is immediately important because area-wide eradication plans involving the sterile in ...	2003	12689645
depletion of gim5 causes cellular fragility, a decreased glycosome number, and reduced levels of ether-linked phospholipids in trypanosomes.	microbody division in mammalian cells, trypanosomes, and yeast depends on the pex11 microbody membrane proteins. the function of pex11 is not understood, and the suggestion that it affects microbody (peroxisome) numbers in mammals and yeast, because it plays a role in beta-oxidation of fatty acids, is controversial. pex11 and two pex11-related proteins, gim5a and gim5b, are the predominant membrane proteins of the microbodies (glycosomes) of trypanosoma brucei. the compartmentation of glycosomal ...	2003	12829709
control of tsetse flies and trypanosomes using molecular genetics.	tsetse flies (diptera: glossinidae) are important agricultural and medical vectors transmitting the african trypanosomes, the agents of sleeping sickness disease in humans and various diseases in animals (nagana). while the prevalence of disease has increased to epidemic proportions, lack of a mammalian vaccine and affordable and effective drugs have hindered disease control. trypanosomiasis management relies heavily on the control of its single insect vector, the tsetse fly. despite the effecti ...	2003	12878419
comparative genomics of insect-symbiotic bacteria: influence of host environment on microbial genome composition.	commensal symbionts, thought to be intermediary amid obligate mutualists and facultative parasites, offer insight into forces driving the evolutionary transition into mutualism. using macroarrays developed for a close relative, escherichia coli, we utilized a heterologous array hybridization approach to infer the genomic compositions of a clade of bacteria that have recently established symbiotic associations: sodalis glossinidius with the tsetse fly (diptera, glossina spp.) and sitophilus oryza ...	2003	14602646
gene expression level influences amino acid usage, but not codon usage, in the tsetse fly endosymbiont wigglesworthia.	wigglesworthia glossinidia brevipalpis, the obligate bacterial endosymbiont of the tsetse fly glossina brevipalpis, is characterized by extreme genome reduction and at nucleotide composition bias. here, multivariate statistical analyses are used to test the hypothesis that mutational bias and genetic drift shape synonymous codon usage and amino acid usage of wigglesworthia. the results show that synonymous codon usage patterns vary little across the genome and do not distinguish genes of putativ ...	2003	12949182
gpi transamidase of trypanosoma brucei has two previously uncharacterized (trypanosomatid transamidase 1 and 2) and three common subunits.	glycosylphosphatidylinositol (gpi) anchor is a membrane attachment mechanism for cell surface proteins widely used in eukaryotes. gpis are added to proteins posttranslationally by a complex enzyme, gpi transamidase. previous studies have shown that human and saccharomyces cerevisiae gpi transamidases are similar and consist of five homologous components: gaa1, gpi8, pig-s, pig-t, and pig-u in humans and gaa1p, gpi8p, gpi17p, gpi16p, and cdc91p in s. cerevisiae. we report that gpi transamidase of ...	2003	12958211
monitoring the developmental status of trypanosoma brucei gambiense in the tsetse fly by means of pcr analysis of anal and saliva drops.	teneral glossina palpalis gambiensis (diptera: glossinidae) were infected with a culture of procyclic forms of trypanosoma brucei gambiense using a single-bloodmeal membrane feeding technique. the infection was monitored by analysing the saliva (mature infection) and anal drop (midgut infection) of each fly at different post-infection times both by microscopic observation and polymerase chain reaction (pcr). amplification revealed many more positive anal drops than microscopy. the monitoring sho ...	2003	14516928
abdominal pericardial sinus: a neurohemal site in the tsetse and other cyclorraphan flies.	an ultrastructural study of the heart of the tsetse fly, glossina morsitans, and of several other species of cyclorraphan flies revealed that the ventral region of the heart of adult flies is supported by a muscular septum not present in the larval stage. the pericardial septum of the adult heart is composed laterally of alary muscles and a central longitudinal muscle that extends the length of the abdominal aorta, whereas the larval heart is supported ventrally only by alary muscles and strands ...	2003	14765650
partial characterisation of a trypanosome-lysing factor from the midgut of the desert locust, schistocerca gregaria.	screening and biochemical characterisation of trypanosome-lysing factor (trypanolysin) from non-vector insect, schistocerca gregaria.	2003	15248675
the effect of age on the mating competitiveness of male glossina fuscipes fuscipes and g. palpalis palpalis.	the effect of age on male glossina fuscipes fuscipes, newstead, and glossina palpalis palpalis, austin (diptera: glossinidae) competiveness were investigated with a view to estimate optimal age for sterile male release. sterile insect technique involves the mass production, sterilization and sequential release of males of the target species to out compete the wild male population. mating between released sterile males and wild females produce inviable progeny and the population is reduced over s ...	2003	15841229
characterization of microsatellite markers in the tsetse fly, glossina pallidipes (diptera: glossinidae).	glossina pallidipes is a vector of african trypanosomiasis. here we characterize eight new polymorphic microsatellite loci in 288 g. pallidipes sampled from 12 kenya populations. the number of alleles per locus ranged from four to 36 with a mean of 20.5 +/- 10.1. expected single locus heterozygosities varied from 0.044 to 0.829. heterozygosity averaged 0.616 +/- 0.246. no linkage disequilibrium was found. we also report results in eight other tsetse species estimated by using the primers develop ...	2003	16718306
antigenic variation and the african trypanosome genome.	african trypanosomes are protozoan parasites that reside in the mammalian bloodstream where they constantly confront the immune responses directed against them. they keep one-step-ahead of the immune system by continually switching from the expression of one variant surface glycoprotein (vsg) on their surface to the expression of another immunologically distinct vsg-a phenomenon called antigenic variation. about 1000 vsg genes (vsgs) and pseudo-vsgs are scattered throughout the trypanosome genom ...	2003	12659976
phosphorylation of gpeet procyclin is not necessary for survival of trypanosoma brucei procyclic forms in culture and in the tsetse fly midgut.		2003	12615329
essential roles for gpi-anchored proteins in african trypanosomes revealed using mutants deficient in gpi8.	the survival of trypanosoma brucei, the causative agent of sleeping sickness and nagana, is facilitated by the expression of a dense surface coat of glycosylphosphatidylinositol (gpi)-anchored proteins in both its mammalian and tsetse fly hosts. we have characterized t. brucei gpi8, the gene encoding the catalytic subunit of the gpi:protein transamidase complex that adds preformed gpi anchors onto nascent polypeptides. deletion of gpi8 (to give deltagpi8) resulted in the absence of gpi-anchored ...	2003	12631733
the major protein in the midgut of teneral glossina morsitans morsitans is a molecular chaperone from the endosymbiotic bacterium wigglesworthia glossinidia.	molecules in the midgut of the tsetse fly (diptera: glossinidiae) are thought to play an important role in the life cycle of african trypanosomes by influencing their initial establishment in the midgut and subsequent differentiation events that ultimately affect parasite transmission. it is thus important to determine the molecular composition of the tsetse midgut to aid in understanding disease transmission by these medically important insect vectors. here, we report that the most abundant pro ...	2002	12530210
seasonal variations in the distribution and abundance of the tsetse fly, glossina morsitans morsitans in eastern zambia.	the seasonal changes in the distribution of glossina morsitans morsitans westwood (diptera: glossinidae) and its main host, cattle, were examined in a cultivated area of the plateau of eastern zambia. during four consecutive years, the tsetse and cattle populations were monitored along a fly-round transect traversing the two main vegetation types in the study area. these were miombo, a one-storied open woodland with the genera brachystegia and julbernardia dominant, and munga, a one- or two-stor ...	2002	12109711
syntheses of racemic and diastereomeric mixtures of 3,7,11,15-tetramethylhentriacontane and 4,8,12,16-tetramethyldotriacontane, the cuticular tetramethylalkanes of the tsetse fly, glossina brevipalpis.	cuticular hydrocarbons of the tsetse fly, glossina brevipalpis, contain 3,7,11,15-tetramethylhentriacontane and 4,8,12,16-tetramethyldotriacontane as possible candidates for its contact sex pheromone. these were synthesized as racemic and diastereomeric mixtures starting from racemic citronellol and employing phenyl-sulfone-mediated chain-elongation as the key reaction.	2002	12005053
area-wide biological control of disease vectors and agents affecting wildlife.	two examples of area-wide programmes, employing the sterile insect technique (sit), which have eradicated a parasite and a disease vector common to domestic and wild animals are described. new world screwworm (nws), cochliomyia hominivorax, caused significant morbidity and mortality of livestock and wild mammals in tropical and subtropical areas of america before eradication was achieved in north america using the sit and other components of an integrated pest management (ipm) programme. movemen ...	2002	11974628
campaign launched to eliminate tsetse fly, which has turned much of africa into a green desert.		2002	12083713
glycosylphosphatidylinositol-anchored surface molecules of trypanosoma congolense insect forms are developmentally regulated in the tsetse fly.	procyclic culture forms of trypanosoma congolense have been shown to express a glutamic acid/alanine-rich protein (garp) on their surface. by labelling t. congolense procyclic culture forms with glycosylphosphatidylinositol (gpi) precursors, we show that garp is bound to the membrane by a gpi anchor and demonstrate the presence of two additional gpi-anchored surface molecules of 24-34 and 58 kda that are abundantly expressed. the 24-34 kda molecule, which is recognised by monoclonal antibodies t ...	2002	11755181
ku is important for telomere maintenance, but not for differential expression of telomeric vsg genes, in african trypanosomes.	trypanosome antigenic variation, involving differential expression of variant surface glycoprotein (vsg) genes, has a strong association with telomeres and with dna recombination. all expressed vsgs are telomeric, and differential activation involves recombination into the telomeric environment or silencing/activation of subtelomeric promoters. a number of pathogen contingency gene systems associated with immune evasion involve telomeric loci, which has prompted speculation that chromosome ends ...	2002	11919193
cloning and functional expression of a fat body-specific chitinase cdna from the tsetse fly, glossina morsitans morsitans.	a chitinase cdna, gchit1 was isolated from glossina morsitans morsitans and shown to be specifically expressed in fat body tissue. gchit1 is encoded by a 1.6 kb mrna with a putative open reading frame (orf) of 460 amino acids (predicted pi=7.5, m.w.=51kda) that contains a signal peptide domain and two potential n-linked glycosylation sites. the orf exhibits homology to various chitinases characterized from insects. it has the conserved catalytic site residues and the cysteine-rich 3'-end domain ...	2002	12213234
parasitological prevalence of bovine trypanosomosis in kindo koisha district, wollaita zone, south ethiopia.	a cross sectional survey to determine the distribution and prevalence of trypanosomosis was conducted in kindo koisha district, in the wollaita zone in southern ethiopia. a total of 1 008 adult cattle was examined at eight different localities. dark field examination of the buffy coat, as well as stained thin blood film examination and packed cell volume (pcv) evaluation were the diagnostic techniques used. the overall prevalence of bovine trypanosomosis was 15 %. among the positive animals, 108 ...	2002	12233995
the cell biology of parasitism in trypanosoma brucei: insights and drug targets from genomic approaches?	the african trypanosome, trypanosoma brucei exhibits a complex, digenetic life cycle that alternates between the tsetse fly vector and the mammalian host. the life cycle is characterised by a complex series of cell type differentiations and variations in metabolism. in addition the trypanosome exhibits a particular cell biology that has become adapted for its role as a parasite. this article places some of these areas in a frame-work that considers the role of cellular processes in parasitism. i ...	2002	11860364
population structure of the tsetse fly glossina pallidipes estimated by allozyme, microsatellite and mitochondrial gene diversities.	diversities at nuclear and mitochondrial loci were examined in eleven natural populations of glossina pallidipes from east and southern africa. alleles in each class of loci are assumed to be selectively neutral. allozyme gene diversities (heterozygosities) averaged over eight loci were 0.146 among seven kenya populations and 0.201 among four southern african populations. microsatellite diversity averaged over three loci was 0.250 in kenya and only 0.218 in southern africa. mitochondrial diversi ...	2002	11841501
pan african group takes lead against the tsetse fly.		2002	11879881
odor composition of preferred (buffalo and ox) and nonpreferred (waterbuck) hosts of some savanna tsetse flies.	a previous study on the feeding responses of tsetse flies, glossina morsitans morsitans, implicated the existence of allomonal barriers, both volatile and nonvolatile, on the nonpreferred host, waterbuck, kobus defassa. in the present study, electroantennogram-active compounds in odors from waterbuck were compared with those of two preferred hosts of tsetse flies, buffalo, syncerus caffer, and ox, bos indicus. odors from the three bovids were trapped on activated charcoal and/or reverse-phase (o ...	2002	12049234
molecular characterization of three gut genes from glossina morsitans morsitans: cathepsin b, zinc-metalloprotease and zinc-carboxypeptidase.	insect gut enzymes are involved in digestion of dietary proteins. additionally, these enzymes have been implicated in the process of pathogen establishment in several insects including the tsetse fly (diptera:glossinidae), which is the vector for african trypanosomes. both the male and female tsetse can transmit trypanosomes and are strict blood feeders during all stages of their development. here, we describe the molecular characterization of three gut genes: cathepsin b (gmcatb), zinc-metallop ...	2002	11841503
[african trypanosomiasis--a rare imported disease].	this year at least nine cases of african trypanosomiasis have occurred among europeans visiting the serengeti park in tanzania. one of them was a 26-year-old norwegian woman who was bitten by a tsetse fly in her face. she developed fever, nausea and other symptoms, and had thrombocytopenia and pathological liver values; trypanosoma parasites were demonstrated in her blood. the recommended drug, suramin, was not readily available in tanzania and she was transported to oslo. the diagnosis was conf ...	2002	11851292
[trypanosomiasis--a real risk for tourists visiting national parks in tanzania].	african sleeping sickness is no longer a rare disease among tourists visiting national parks in tanzania. the disease is caused by a parasite, trypanosoma brucei, which is transmitted by the tsetse fly. two species infect humans: trypanosoma brucci gambiense and trypanosoma brucei rhodesiense; the last form is re-emerging in parts of africa. untreated this disease carries a mortality of nearly 100%. this article describes a case of african sleeping sickness in a tourist visiting tanzania, which ...	2002	11851293
chemotherapy of human african trypanosomiasis.	human african trypanosomiasis or sleeping sickness is resurgent [1,2]. the disease is caused by subspecies of the parasitic haemoflagellate, trypanosoma brucei. infection starts with the bite of an infected tsetse fly (glossina spp.). parasites move from the site of infection to the draining lymphatic vessels and blood stream. the parasites proliferate within the bloodstream and later invade other tissues including the central nervous system. once they have established themselves within the cns, ...	2002	11860365
immunopeptides in the defense reactions of glossina morsitans to bacterial and trypanosoma brucei brucei infections.	several dipteran insects are vectors of parasites causing major human infectious diseases. among these, the tsetse fly, glossina spp., is responsible for the transmission of trypanosomes, the pathogens responsible for sleeping sickness in africa. a better understanding of insect-parasite interactions will help establish new strategies to fight this important often fatal disease. antimicrobial peptides (amps) are part of the humoral immune response in insects during bacterial, fungal and parasiti ...	2002	11886771
microsatellite diversities and gene flow in the tsetse fly, glossina morsitans s.l.	tsetse flies occupy discontinuous habitats and gene flow among them needs to be investigated in anticipation of area-wide control programs. genetic diversities were estimated at six microsatellite loci in seven glossina morsitans submorsitans newstead (diptera: glossinidae) populations and five microsatellite loci in six g. m. morsitans westwood populations. nei's unbiased diversities were 0.808 and 76 alleles in g. m. submorsitans and 0.727 and 55 alleles in g. m. morsitans. diversities were le ...	2002	12243230
sustainability of tsetse control by subsequent treatment of 10% of a previously treated ugandan cattle population with 1% w/v deltamethrin.	this study was conducted in masaba and masafu sub-counties, busia district, uganda to assess the effect on the tsetse fly population of first treating all cattle with 1% w/v deltamethrin pour-on for a few months, followed by treating 10% of the cattle population. treatment of all cattle for 6 months resulted in a significant reduction in the density of tsetse flies from 6.3 to 0.1 flies/trap/day (ftd), a 98.4% reduction. during the same period, the point prevalence of bovine trypanosomosis dropp ...	2002	11969108
galactose metabolism is essential for the african sleeping sickness parasite trypanosoma brucei.	the tsetse fly-transmitted protozoan parasite trypanosoma brucei is the causative agent of human african sleeping sickness and the cattle disease nagana. the bloodstream form of the parasite uses a dense cell-surface coat of variant surface glycoprotein to escape the innate and adaptive immune responses of the mammalian host and a highly glycosylated transferrin receptor to take up host transferrin, an essential growth factor. these glycoproteins, as well as other flagellar pocket, endosomal, an ...	2002	11983889
serum xanthine oxidase: origin, regulation, and contribution to control of trypanosome parasitemia.	african trypanosomiasis is caused by salivarian trypanosomes, tsetse fly-transmitted protozoa that inhabit the blood plasma, lymph and interstitial fluids, and, in the case of trypanosoma brucei species, also the cerebrospinal fluid of mammal hosts. trypanosomiasis in people and domestic animals manifests as recurring waves of parasites in the blood and is typically fatal. in contrast, trypanosomiasis in cape buffaloes, which are naturally selected to resist the disease, is characterized by the ...	2002	11970851
fold-recognition analysis predicts that the tag protein family shares a common domain with the helix-hairpin-helix dna glycosylases.	the escherichia coli protein tag is traditionally regarded as an archetype of one of four classes of n-alkylpurine dna glycosylases. however, its structure and phylogenetic relationship to other glycosylases remains a mystery. fold-recognition and sequence profile analyses suggest that tag shares the catalytic domain with helix-hairpin-helix (hhh) glycosylases such as muty, alka and endoiii, but its n- and c-termini together form a unique his2cys2 cluster. the findings presented in this paper pr ...	2002	12509243
identification of major soluble salivary gland proteins in teneral glossina morsitans morsitans.	salivary glands of tsetse flies (diptera: glossinidiae) contain molecules that are involved in preventing blood clotting during feeding as well as molecules thought to be intimately associated with trypanosome development and maturation. here we present a protein microchemical analysis of the major soluble proteins of the salivary glands of glossina morsitans morsitans, an important vector of african trypanosomes. differential solubilization of salivary proteins was followed by reverse-phase, hi ...	2002	12213241
ex vivo and in vitro identification of a consensus promoter for vsg genes expressed by metacyclic-stage trypanosomes in the tsetse fly.	the trypanosome variant surface glycoprotein (vsg) is first expressed during differentiation to the infective, metacyclic population in tsetse fly salivary glands. unlike the vsg genes expressed by bloodstream form trypanosomes, metacyclic vsgs (mvsgs) have their own promoters. the scarcity of metacyclic cells has meant that only indirect approaches have been used to study these promoters, and not even their identities have been agreed on. here, we isolated trypanosomes by dissection from saliva ...	2002	12477800
growth and mortality in sheep and goats under high tsetse challenge in kenya.	trypanosomosis is a major impediment to livestock production and economic development in those areas of africa where it is endemic. although small ruminants appear to perform better than cattle in various agro-ecological zones, the importance of trypanosomosis has not been extensively investigated in these livestock. this study was designed to investigate the prevalence of trypanosomosis in sheep and goats in an endemic area and to evaluate the performance of different breeds under high tsetse c ...	2002	12537387
partial structure of glutamic acid and alanine-rich protein, a major surface glycoprotein of the insect stages of trypanosoma congolense.	the tsetse fly transmitted salivarian trypanosome, trypanosoma congolense of the subgenus nanomonas, is the most significant of the trypanosomes with respect to the pathology of livestock in sub-saharan africa. unlike the related trypanosome trypanosoma brucei of the subgenus trypanozoon, the major surface molecules of the insect stages of t. congolense are poorly characterized. here, we describe the purification and structural characterization of the glutamic acid and alanine-rich protein, one ...	2002	12368279
[tsetse fly wings, an identity card of the insect?].	the size of tsetse flies is often associated with population dynamics and vectorial capacity parameters. adult fly size is generally estimated from measurements of wing segments. to take measure of the wing, a semi-automatic software was developed by cirad-emvt and ird. it was used in wild populations of glossina tachinoides westwood and g. palpalis gambiensis vanderplank (diptera: glossinidae) trapped near bobo-dioulasso, burkina faso. from an numeric picture of the wing, the software calculate ...	2002	12375372
photographic polytene chromosome maps for glossina morsitans submorsitans (diptera: glossinidae): cytogenetic analysis of a colony with sex-ratio distortion.	photographic polytene chromosome maps from trichogen cells of pharate adult glossina morsitans submorsitans were constructed. using the standard system employed to map polytene chromosomes of drosophila, the characteristic landmarks were described for the x chromosome and the two autosomes (l1 and l2). sex-ratio distortion, which is expressed in male g. m. submorsitans, was found to be associated with an x chromosome (x8) that contains three inversions in each arm. preliminary data indicate no d ...	2002	12416619
proventriculus-specific cdnas characterized from the tsetse, glossina morsitans morsitans.	peritrophic matrix (peritrophic membrane or pm) is an important structure in the gut of most insects at some stage in their development. it is composed of chitin, proteins and proteoglycans. multiple roles for the pm ranging from partitioning of digestive enzymes and food to protection of gut epithelial cells from viral and parasitic invasion have been proposed. while most adult members of diptera have a type i pm synthesized in response to a blood meal, the medically and agriculturally importan ...	2002	12429118
stage-specific requirement of a mitogen-activated protein kinase by trypanosoma brucei.	in cycling between the mammalian host and the tsetse fly vector, african trypanosomes undergo adaptive differentiation steps that are coupled to growth control. the signaling pathways underlying these cellular processes are largely unknown. mitogen-activated protein kinases (mapks) are known mediators of growth and differentiation in other eukaryotic organisms. to establish the function of a mapk homologue, tbmapk2, in t. brucei, a null mutant was constructed. bloodstream forms of a deltamapk2/d ...	2002	12429824
the human serum resistance associated gene is ubiquitous and conserved in trypanosoma brucei rhodesiense throughout east africa.	the human serum resistance associated (sra) gene isolated from a ugandan strain of trypanosoma brucei rhodesiense has been shown to be capable by itself of conferring the trait of human infectivity on t.b. brucei by transfection. this gene has also been identified in several other isolates of t.b. rhodesiense, but not in the other human pathogenic trypanosome in africa, t.b. gambiense, casting doubt on its ubiquity and function. here, we show that this gene occurs in t.b. rhodesiense from sleepi ...	2002	12798017
identification and properties of microsatellite markers in tsetse flies glossina morsitans sensu lato (diptera: glossinidae).	genomic libraries enriched for simple sequence repeats were constructed for glossina morsitans morsitans, g. m. submorsitans, and g. m. centralis. sixteen microsatellite markers were isolated from the libraries and evaluated on flies from natural g. m. morsitans populations and other glossina species in the morsitans and palpalis species groups. the primers amplified appropriate sized dna fragments in the morsitans and palpalis groups. in g. morsitans s.l., eight of 12 dinucleotide repeats and f ...	2001	16479272
characterization of the adenosine deaminase-related growth factor (adgf) gene family in drosophila.	a novel family of growth factors, with sequence similarity to adenosine deaminase, has been identified in various organisms including flesh fly, tsetse fly, sand fly, mollusk and human. the human homologue, cecr1, is a candidate gene for the genetic disorder cat eye syndrome. here, we describe six members of this growth factor family in drosophila and two in vertebrates. the six drosophila genes, named adenosine deaminase-related growth factors (adgf), are found at three different chromosomal lo ...	2001	11738815
antigenic variation in trypanosomes: enhanced phenotypic variation in a eukaryotic parasite.	african trypanosomes are unicellular, eukaryotic parasites that live extracellularly in a wide range of mammals, including humans. they have a surface coat, composed of variant surface glycoprotein (vsg), which probably is essential and acts as a defence against general innate immunity and against acquired immunity directed at invariant surface antigens. in effect, the vsg is the only antigen that the host can target, and each trypanosome expresses only one vsg. to counter specific antibodies ag ...	2001	11461029
genetic differentiation of glossina morsitans centralis populations.	variation at mitochondrial and microsatellite loci was used to study the breeding and dispersal structure of glossina morsitans centralis, in six natural populations from botswana, the caprivi strip (namibia), zambia, and in a laboratory culture derived from singida, tanzania. only seven mitochondrial haplotypes were found. mean diversity averaged over the six natural populations was 0.216 +/- 0.085. the fixation index fst = 0.866 indicated a high degree of genetic differentiation among populati ...	2001	11520361