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1.
Parasit Vectors ; 15(1): 447, 2022 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-36447246

RESUMO

BACKGROUND: Tsetse control is considered an effective and sustainable tactic for the control of cyclically transmitted trypanosomosis in the absence of effective vaccines and inexpensive, effective drugs. The sterile insect technique (SIT) is currently used to eliminate tsetse fly populations in an area-wide integrated pest management (AW-IPM) context in Senegal. For SIT, tsetse mass rearing is a major milestone that associated microbes can influence. Tsetse flies can be infected with microorganisms, including the primary and obligate Wigglesworthia glossinidia, the commensal Sodalis glossinidius, and Wolbachia pipientis. In addition, tsetse populations often carry a pathogenic DNA virus, the Glossina pallidipes salivary gland hypertrophy virus (GpSGHV) that hinders tsetse fertility and fecundity. Interactions between symbionts and pathogens might affect the performance of the insect host. METHODS: In the present study, we assessed associations of GpSGHV and tsetse endosymbionts under field conditions to decipher the possible bidirectional interactions in different Glossina species. We determined the co-infection pattern of GpSGHV and Wolbachia in natural tsetse populations. We further analyzed the interaction of both Wolbachia and GpSGHV infections with Sodalis and Wigglesworthia density using qPCR. RESULTS: The results indicated that the co-infection of GpSGHV and Wolbachia was most prevalent in Glossina austeni and Glossina morsitans morsitans, with an explicit significant negative correlation between GpSGHV and Wigglesworthia density. GpSGHV infection levels > 103.31 seem to be absent when Wolbachia infection is present at high density (> 107.36), suggesting a potential protective role of Wolbachia against GpSGHV. CONCLUSION: The result indicates that Wolbachia infection might interact (with an undefined mechanism) antagonistically with SGHV infection protecting tsetse fly against GpSGHV, and the interactions between the tsetse host and its associated microbes are dynamic and likely species specific; significant differences may exist between laboratory and field conditions.


Assuntos
Coinfecção , Glossinidae , Infertilidade , Moscas Tsé-Tsé , Animais , Citomegalovirus , Hipertrofia , Glândulas Salivares
2.
PLoS Negl Trop Dis ; 15(11): e0009989, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34843478

RESUMO

BACKGROUND: Glossina austeni and Glossina brevipalpis (Diptera: Glossinidae) are the sole cyclical vectors of African trypanosomes in South Africa, Eswatini and southern Mozambique. These populations represent the southernmost distribution of tsetse flies on the African continent. Accurate knowledge of infested areas is a prerequisite to develop and implement efficient and cost-effective control strategies, and distribution models may reduce large-scale, extensive entomological surveys that are time consuming and expensive. The objective was to develop a MaxEnt species distribution model and habitat suitability maps for the southern tsetse belt of South Africa, Eswatini and southern Mozambique. METHODOLOGY/PRINCIPAL FINDINGS: The present study used existing entomological survey data of G. austeni and G. brevipalpis to develop a MaxEnt species distribution model and habitat suitability maps. Distribution models and a checkerboard analysis indicated an overlapping presence of the two species and the most suitable habitat for both species were protected areas and the coastal strip in KwaZulu-Natal Province, South Africa and Maputo Province, Mozambique. The predicted presence extents, to a small degree, into communal farming areas adjacent to the protected areas and coastline, especially in the Matutuíne District of Mozambique. The quality of the MaxEnt model was assessed using an independent data set and indicated good performance with high predictive power (AUC > 0.80 for both species). CONCLUSIONS/SIGNIFICANCE: The models indicated that cattle density, land surface temperature and protected areas, in relation with vegetation are the main factors contributing to the distribution of the two tsetse species in the area. Changes in the climate, agricultural practices and land-use have had a significant and rapid impact on tsetse abundance in the area. The model predicted low habitat suitability in the Gaza and Inhambane Provinces of Mozambique, i.e., the area north of the Matutuíne District. This might indicate that the southern tsetse population is isolated from the main tsetse belt in the north of Mozambique. The updated distribution models will be useful for planning tsetse and trypanosomosis interventions in the area.


Assuntos
Glossinidae/fisiologia , Controle de Insetos/métodos , Insetos Vetores/fisiologia , Distribuição Animal , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/transmissão , Ecossistema , Essuatíni/epidemiologia , Glossinidae/classificação , Insetos Vetores/classificação , Moçambique/epidemiologia , África do Sul/epidemiologia
3.
Trop Anim Health Prod ; 53(2): 305, 2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-33950335

RESUMO

Occurrence of nutritional stress (due to depletion of fat reserves) in tsetse flies, associated with inadequate levels of access to blood meals, enhances susceptibility of the flies to trypanosome infection. Thus, in a tsetse-infested area, a spatial gradient of reducing tsetse habitat quality is potentially a gradient of increasing prospects for occurrence of stress in tsetse flies. This study investigated prevalence of trypanosome infection in Glossina morsitans morsitans and G. pallidipes along a transect line hypothesised to represent such a gradient, in relation to the edge of the tsetse belt and distribution of human settlements. This was undertaken in three sites located in Lundazi, Mpika and Rufunsa districts, respectively, in north-eastern Zambia. Human settlement was concentrated at the edge of the tsetse belt in the Mpika and Rufunsa sites and evenly distributed along transect line in the Lundazi site. Tsetse fly samples were collected using black-screen fly rounds and Epsilon traps. Detection of trypanosome infection was by dissection and microscopy in Lundazi and Mpika sites and loop-mediated isothermal amplification (LAMP) test in Rufunsa site. Multiple logistic regression models were applied to determine whether the following factors, 'change in distance from edge of tsetse belt', 'tsetse sampling method' and 'sex of tsetse fly', had effect on 'prevalence of trypanosome infection' in the tsetse flies. Only 'increase in distance from the edge of tsetse belt' for G. m. morsitans was significantly associated with 'prevalence of trypanosome infection' in the flies, in the Mpika and Rufunsa sites. Distance was associated with reduced likelihood of infection with 'one or more subgenera of trypanosomes' and with 'Nannomonas trypanosomes', in the case of 'all sites collectively', 'Lundazi and Mpika sites collectively', Mpika site alone, and Rufunsa site alone. Per site, increase in distance entailed reduced prospects for Trypanozoon infection but only in the Mpika and Rufunsa sites. We conclude that in the Mpika and Rufunsa sites, increase in distance from human settlements entailed reduced likelihood of trypanosome infection, likely due to reducing tsetse habitat degradation, increasing availability of hosts, and hence increasing levels of nutrition and fat reserves, thus enhancing tsetse immunity against trypanosome infection.


Assuntos
Glossinidae , Trypanosoma , Moscas Tsé-Tsé , Animais , Humanos , Técnicas de Diagnóstico Molecular , Técnicas de Amplificação de Ácido Nucleico , Prevalência , Zâmbia/epidemiologia
4.
J Med Entomol ; 58(2): 891-899, 2021 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-33118036

RESUMO

The effect of human-associated habitat degradation on tsetse populations is well established. However, more insights are needed into how gradual human encroachment into tsetse fly belts affect tsetse populations. This study investigated how wing vein length, wing fray categories, and hunger stages, taken as indicators of body size, age, and levels of access to hosts, respectively, in Glossina morsitans morsitans Westwood (Diptera: Glossinidae) and Glossina pallidipes Austen (Diptera: Glossinidae), varied along a transect from the edge into inner parts of the tsetse belt, in sites that had human settlement either concentrated at the edge of belt or evenly distributed along transect line, in north-eastern Zambia. Black-screen fly round and Epsilon traps were used in a cross-sectional survey on tsetse flies at three sites, following a transect line marked by a road running from the edge into the inner parts of the tsetse belt, per site. Two sites had human settlement concentrated at or close to the edge of the tsetse belt, whereas the third had human settlement evenly distributed along the transect line. Where settlements were concentrated at the edge of tsetse belt, increase in distance from the settlements was associated with increase in wing vein length and a reduction in the proportion of older, and hungry, tsetse flies. Increase in distance from human settlements was associated with improved tsetse well-being, likely due to increase in habitat quality due to decrease in effects of human activities.


Assuntos
Tamanho Corporal , Glossinidae/fisiologia , Fome , Moscas Tsé-Tsé/fisiologia , Animais , Bovinos , Estudos Transversais , Ecossistema , Humanos , Controle de Insetos , Insetos Vetores , População Rural , Asas de Animais , Zâmbia
5.
Parasit Vectors ; 13(1): 219, 2020 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-32349788

RESUMO

BACKGROUND: Tsetse flies (Diptera: Glossinidae) and tabanids (Diptera: Tabanidae) are haematophagous insects of medical and veterinary importance due to their respective role in the biological and mechanical transmission of trypanosomes. Few studies on the distribution and relative abundance of both families have been conducted in Mozambique since the country's independence. Despite Nicoadala, Mozambique, being a multiple trypanocidal drug resistance hotspot no information regarding the distribution, seasonality or infection rates of fly-vectors are available. This is, however, crucial to understanding the epidemiology of trypanosomosis and to refine vector management. METHODS: For 365 days, 55 traps (20 NGU traps, 20 horizontal traps and 15 Epsilon traps) were deployed in three grazing areas of Nicoadala District: Namitangurine (25 traps); Zalala (15 traps); and Botao (15 traps). Flies were collected weekly and preserved in 70% ethanol. Identification using morphological keys was followed by molecular confirmation using cytochrome c oxidase subunit 1 gene. Trap efficiency, species distribution and seasonal abundance were also assessed. To determine trypanosome infection rates, DNA was extracted from the captured flies, and submitted to 18S PCR-RFLP screening for the detection of Trypanosoma. RESULTS: In total, 4379 tabanids (of 10 species) and 24 tsetse flies (of 3 species), were caught. NGU traps were more effective in capturing both the Tabanidae and Glossinidae. Higher abundance and species diversity were observed in Namitangurine followed by Zalala and Botao. Tabanid abundance was approximately double during the rainy season compared to the dry season. Trypanosoma congolense and T. theileri were detected in the flies with overall infection rates of 75% for tsetse flies and 13% for tabanids. Atylotus agrestis had the highest infection rate of the tabanid species. The only pathogenic trypanosome detected was T. congolense. CONCLUSIONS: Despite the low numbers of tsetse flies captured, it can be assumed that they are still the cyclical vectors of trypanosomosis in the area. However, the high numbers of tabanids captured, associated to their demonstrated capacity of transmitting trypanosomes mechanically, suggest an important role in the epidemiology of trypanosomosis in the Nicoadala district. These results on the composition of tsetse and tabanid populations as well as the observed infection rates, should be considered when defining strategies to control the disease.


Assuntos
Dípteros/parasitologia , Resistência a Medicamentos , Glossinidae/parasitologia , Insetos Vetores/parasitologia , Trypanosoma/efeitos dos fármacos , Tripanossomíase/transmissão , Animais , Dípteros/classificação , Dípteros/genética , Glossinidae/classificação , Glossinidae/genética , Moçambique/epidemiologia , Estações do Ano , Tripanossomicidas/farmacologia , Trypanosoma/genética , Trypanosoma congolense/efeitos dos fármacos , Trypanosoma congolense/genética , Tripanossomíase/classificação , Tripanossomíase/epidemiologia , Tripanossomíase/parasitologia , Moscas Tsé-Tsé/genética
6.
BMC Microbiol ; 18(Suppl 1): 161, 2018 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-30470172

RESUMO

BACKGROUND: Tsetse flies (Diptera: Glossinidae) are the vectors of African trypanosomosis, the causal agent of sleeping sickness in humans and nagana in animals. Glossina fuscipes fuscipes is one of the most important tsetse vectors of sleeping sickness, particularly in Central Africa. Due to the development of resistance of the trypanosomes to the commonly used trypanocidal drugs and the lack of effective vaccines, vector control approaches remain the most effective strategies for sustainable management of those diseases. The Sterile Insect Technique (SIT) is an effective, environment-friendly method for the management of tsetse flies in the context of area-wide integrated pest management programs (AW-IPM). This technique relies on the mass-production of the target insect, its sterilization with ionizing radiation and the release of sterile males in the target area where they will mate with wild females and induce sterility in the native population. It has been shown that Glossina pallidipes salivary gland hypertrophy virus (GpSGHV) infection causes a decrease in fecundity and fertility hampering the maintenance of colonies of the tsetse fly G. pallidipes. This virus has also been detected in different species of tsetse files. In this study, we evaluated the impact of GpSGHV on the performance of a colony of the heterologous host G. f. fuscipes, including the flies' productivity, mortality, survival, flight propensity and mating ability and insemination rates. RESULTS: Even though GpSGHV infection did not induce SGH symptoms, it significantly reduced all examined parameters, except adult flight propensity and insemination rate. CONCLUSION: These results emphasize the important role of GpSGHV management strategy in the maintenance of G. f. fuscipes colonies and the urgent need to implement measures to avoid virus infection, to ensure the optimal mass production of this tsetse species for use in AW-IPM programs with an SIT component.


Assuntos
Citomegalovirus/patogenicidade , Glossinidae/virologia , Moscas Tsé-Tsé/virologia , Animais , Feminino , Glossinidae/fisiologia , Hipertrofia , Controle de Insetos , Vírus de Insetos/patogenicidade , Masculino
7.
J Med Entomol ; 53(4): 945-948, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27113105

RESUMO

Human African trypanosomiasis became a neglected disease after the 1960s, when case numbers dropped dramatically. It again became a public health problem in sub-Saharan Africa at the end of the 1990s, when new cases were reported, notably in Central Africa, and specifically in Gabon, where historic foci existed and new cases have been reported. Therefore, the present study reports on an entomological survey conducted in May 2012 to determine the pathogenic trypanosome infection rate in tsetse flies and characterize the diversity of Trypanosoma species in the Ivindo National Park (INP) in northeastern Gabon. Nine Vavoua traps were used to catch tsetse over a 7-days period. All tsetse flies captured were identified to species, dissected, and trypanosome species identified using polymerase chain reaction (PCR). In total, 160 tsetse flies were analyzed, including Glossina palpalis palpalis, Glossina fusca congolense, and Glossina tachinoïdes The trypanosome infection rate of the flies was 6.3 and 31.9% using microscopy and PCR, respectively. The species identified were Trypanosoma congolense savannah type, Trypanosoma brucei brucei, Trypanosoma brucei gambiense, Trypanosoma vivax, and Trypanosoma congolense forest type. Trypanosoma risk index was 0.75 and 7.05 for humans and for animals, respectively. This study illustrates the diversity of Trypanosoma species infecting the tsetse flies in the INP. The simultaneous occurrence of Trypanosoma and tsetse from the palpalis group may suggest that the reservoirs of African animal trypanosomiasis should be carefully monitored in this area.


Assuntos
Glossinidae/parasitologia , Insetos Vetores/parasitologia , Trypanosomatina/fisiologia , Tripanossomíase Africana/epidemiologia , Animais , Biodiversidade , Gabão/epidemiologia , Glossinidae/classificação , Humanos , Insetos Vetores/classificação , Reação em Cadeia da Polimerase , Trypanosomatina/classificação , Tripanossomíase Africana/parasitologia
8.
Bull Soc Pathol Exot ; 109(2): 126-31, 2016 May.
Artigo em Francês | MEDLINE | ID: mdl-26875082

RESUMO

The mangrove area on the Guinea littoral constitutes a favourable habitat for transmission of Trypanosoma brucei gambiens, the parasite causing sleeping sickness also called Human African Trypanosmosis (HAT), due the simultaneous presence of the vector (tsetse flies) and the human hosts. In order to assess the influence of the sea tides on the densities of Glossina palpalis gambiensis (Gpg), major vector of HAT in the mangrove, entomological surveys were performed using two transects, according to tides coefficient (great and small) and tide daily fluctuations (high and low). On each transect, 12 biconical traps were deployed through the mangrove to the continent. In total, up to 612 Gpg were caught, giving a density of 2.13 flies/trap/day (f/t/d). Highest captures were recorded during small tides and more tsetse were caught during the dry season than in the wet season. There were significant differences between captures when considering the different biotopes, and highest tsetse densities were recorded at the junction of the river and the channel of the mangrove (6.17±5.24); and in the channels of mangrove (3.50±3.76), during high tides of small coefficients. The results of this study may be used to improve vector control methods.


Assuntos
Avicennia/parasitologia , Ecossistema , Glossinidae , Ondas de Maré , Moscas Tsé-Tsé , Áreas Alagadas , Animais , Notificação de Doenças/estatística & dados numéricos , Feminino , Guiné/epidemiologia , Masculino , Dinâmica Populacional , Rios , Estações do Ano , Tripanossomíase Africana/parasitologia , Tripanossomíase Africana/transmissão
9.
J Med Entomol ; 52(4): 614-21, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26335467

RESUMO

Infection of tsetse fly with trypanosome parasites could be influenced by its ability to locate vertebrate host(s) in the wild. Generally, the antennae of insects are known to bear chemo-sensory organs (sensilla), which are used for host search among other functions. In order to exploit the potentials of tsetse-search behavior, knowledge of sensilla types on the antennae is desirable. In line with this, the dorsal and ventral surfaces of the antennae of Glossina palpalis and Glossina tachinoides (Westwood) were examined under the scanning electron microscope. Results showed that trichoid and chaetica (subtypes I and II) sensilla are present only on the scape and pedicel, while basiconica (subtypes I and II) and sensory pits are seen on the flagella. Microtrichia are present on all the segments of the antennae with Ca II being most abundant. Specifically, in females of G. tachinoides, there is a near-even distribution of Ca I and Ca II on the pedicel while more number of sensory pits was seen on females than males in both species. This study hypothesizes that host-search efficiency could be influenced by the number of olfactory-sensilla types on the antennae, in which case, females present greater potentials.


Assuntos
Antenas de Artrópodes/anatomia & histologia , Glossinidae/anatomia & histologia , Sensilas/anatomia & histologia , Animais , Antenas de Artrópodes/ultraestrutura , Feminino , Glossinidae/ultraestrutura , Masculino , Microscopia Eletrônica de Varredura , Níger , Nigéria , Sensilas/ultraestrutura
10.
Parasite ; 22: 23, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26187781

RESUMO

In order to minimize risks of pathogen transmission with the development of ecotourism in Gabon, a seasonal inventory has been performed in five contrasted biotopes in Ivindo (INP) and Moukalaba-Doudou (MDNP) National Parks. A total of 10,033 hematophagous flies were captured. The Glossinidae, with six different species identified, was the most abundant group and constitutes about 60% of the captured flies compared to the Stomoxys (6 species also identified) and Tabanidae with 28% and 12%, respectively. The Glossinidae showed a higher rate of capture in primary forest and in research camps. In INP, the Stomoxys showed a higher rate of capture in secondary forest and at village borders, whereas in MDNP the Stomoxys were captured more in the savannah area. Thus, each fly group seemed to reach maximum abundance in different habitats. The Glossinidae were more abundant in primary forest and near research camps while Stomoxys were more abundant in secondary forest and savannah. The Tabanidae did not show a clear habitat preference.


Assuntos
Dípteros , Distribuição Animal , Animais , Ecossistema , Florestas , Gabão , Glossinidae , Pradaria , Umidade , Insetos Vetores , Muscidae , Parques Recreativos , Dinâmica Populacional , Estações do Ano , Especificidade da Espécie , Tripanossomíase Africana/transmissão , Moscas Tsé-Tsé , Viroses/transmissão
11.
Mol Ecol ; 23(8): 2105-17, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24612422

RESUMO

The γ-proteobacterium Arsenophonus and its close relatives (Arsenophonus and like organisms, ALOs) are emerging as a novel clade of endosymbionts, which are exceptionally widespread in insects. The biology of ALOs is, however, in most cases entirely unknown, and it is unclear how these endosymbionts spread across insect populations. Here, we investigate this aspect through the examination of the presence, the diversity and the evolutionary history of ALOs in 25 related species of blood-feeding flies: tsetse flies (Glossinidae), louse flies (Hippoboscidae) and bat flies (Nycteribiidae and Streblidae). While these endosymbionts were not found in tsetse flies, we identify louse flies and bat flies as harbouring the highest diversity of ALO strains reported to date, including a novel ALO clade, as well as Arsenophonus and the recently described Candidatus Aschnera chinzeii. We further show that the origin of ALO endosymbioses extends deep into the evolutionary past of louse flies and bat flies, and that it probably played a major role in the ecological specialization of their hosts. The evolutionary history of ALOs is notably complex and was shaped by both vertical transmission and horizontal transfers with frequent host turnover and apparent symbiont replacement in host lineages. In particular, ALOs have evolved repeatedly and independently close relationships with diverse groups of louse flies and bat flies, as well as phylogenetically more distant insect families, suggesting that ALO endosymbioses are exceptionally dynamic systems.


Assuntos
Evolução Biológica , Dípteros/microbiologia , Gammaproteobacteria/genética , Filogenia , Simbiose , Animais , DNA Bacteriano/genética , Glossinidae/microbiologia , Dados de Sequência Molecular
12.
Infect Genet Evol ; 11(4): 740-5, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21055483

RESUMO

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. morsitans remain refractory to trypanosome infection are largely unknown although it has been demonstrated that G. morsitans mounts a strong immune response to invading pathogens. This study identifies G. morsitans immune-related CLIP domain serine proteases and their inhibitors, serine protease inhibitors (serpin) genes. It further establishes their evolutionary relationships with counterparts in Drosophila melanogaster, Anopheles gambiae, Bombyx mori, Manduca sexta and Culex quinquefasciatus. Multiple sequence alignments show conservation of most secondary structure elements for both CLIPs and serpins. Amino acid composition of the serpin reactive site loop (RSL) indicates that the G. morsitans serpins act through an inhibitory mechanism to the target serine protease. Similar to D. melanogaster and unlike A. gambiae, the transcriptome data suggest that G. morsitans does not contain gene expansions in their CLIP-domain serine protease and serpin families. The presence of alternatively spliced variants in the G. morsitans serpins transcriptome data mirrors that of the D. melanogaster transcriptome.


Assuntos
Evolução Molecular , Regulação da Expressão Gênica , Genômica , Glossinidae/enzimologia , Glossinidae/imunologia , Serina Proteases/genética , Inibidores de Serino Proteinase/genética , Serpinas/genética , Sequência de Aminoácidos , Animais , Perfilação da Expressão Gênica , Glossinidae/classificação , Glossinidae/genética , Humanos , Dados de Sequência Molecular , Filogenia , Alinhamento de Sequência , Serina Proteases/imunologia , Inibidores de Serino Proteinase/imunologia , Serpinas/imunologia
13.
J Virol ; 82(9): 4595-611, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18272583

RESUMO

Several species of tsetse flies can be infected by the Glossina pallidipes salivary gland hypertrophy virus (GpSGHV). Infection causes salivary gland hypertrophy and also significantly reduces the fecundity of the infected flies. To better understand the molecular basis underlying the pathogenesis of this unusual virus, we sequenced and analyzed its genome. The GpSGHV genome is a double-stranded circular DNA molecule of 190,032 bp containing 160 nonoverlapping open reading frames (ORFs), which are distributed equally on both strands with a gene density of one per 1.2 kb. It has a high A+T content of 72%. About 3% of the GpSGHV genome is composed of 15 sequence repeats, distributed throughout the genome. Although sharing the same morphological features (enveloped rod-shaped nucleocapsid) as baculoviruses, nudiviruses, and nimaviruses, analysis of its genome revealed that GpSGHV differs significantly from these viruses at the level of its genes. Sequence comparisons indicated that only 23% of GpSGHV genes displayed moderate homologies to genes from other invertebrate viruses, principally baculoviruses and entomopoxviruses. Most strikingly, the GpSGHV genome encodes homologues to the four baculoviral per os infectivity factors (p74 [pif-0], pif-1, pif-2, and pif-3). The DNA polymerase encoded by GpSGHV is of type B and appears to be phylogenetically distant from all DNA polymerases encoded by large double-stranded DNA viruses. The majority of the remaining ORFs could not be assigned by sequence comparison. Furthermore, no homologues to DNA-dependent RNA polymerase subunits were detected. Taken together, these data indicate that GpSGHV is the prototype member of a novel group of insect viruses.


Assuntos
Vírus de DNA/genética , DNA Circular , Genoma Viral , Glossinidae/genética , Vírus de Insetos/genética , Animais , Sequência de Bases , Hipertrofia , Dados de Sequência Molecular , Fases de Leitura Aberta , Glândulas Salivares
14.
Biochem Genet ; 44(9-10): 471-7, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17103047

RESUMO

We report the development and characterization of three new microsatellite markers in the tsetse fly, Glossina pallidipes (Diptera: Glossinidae). Fifty-eight alleles were scored in 192 individuals representing six natural populations. Allelic diversity ranged from 9 to 28 alleles per locus (mean 19.3 +/- 5.5). Averaged across loci, observed heterozygosity was 0.581 +/- 0.209, and expected heterozygosity was 0.619 +/- 0.181. Cross-species amplifications of the G. pallidipes loci in other tsetse fly taxa are reported.


Assuntos
Glossinidae/genética , Repetições de Microssatélites/genética , Alelos , Animais , Sequência de Bases , Primers do DNA , Glossinidae/classificação , Heterozigoto , Especificidade da Espécie
15.
J Med Entomol ; 40(6): 755-65, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14765650

RESUMO

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 of connective tissue. Thus, unlike the larval stage, and the heart of other insects, the pericardial septum of adult cyclorraphan flies contains a central band of longitudinal muscle, that along with the alary muscle, forms a large pericardial sinus lying between the septum and the heart. Neurosecretory nerves arising from the lateral nerves of the thoracicoabdominal ganglion extend dorsad to the pericardial septum, where they form neuromuscular junctions on the muscle fibers of the pericardial septum or traverse the septum terminating in the pericardial sinus, thereby creating one of the largest neurohemal organs in these flies. In the tsetse fly, some of the neurosecretory fibers also extend between the muscle fibers of the myocardium, and release their material into the lumen of the heart.


Assuntos
Abdome/anatomia & histologia , Glossinidae/anatomia & histologia , Moscas Tsé-Tsé/anatomia & histologia , Animais , Feminino , Glossinidae/classificação , Glossinidae/crescimento & desenvolvimento , Glossinidae/ultraestrutura , Larva , Masculino , Microscopia Eletrônica de Varredura , Fibras Musculares Esqueléticas/ultraestrutura , Miocárdio/ultraestrutura , Moscas Tsé-Tsé/classificação , Moscas Tsé-Tsé/crescimento & desenvolvimento , Moscas Tsé-Tsé/ultraestrutura
16.
Mem. Inst. Oswaldo Cruz ; 93(6): 861-64, Nov.-Dec. 1998. tab
Artigo em Inglês | LILACS | ID: lil-223896

RESUMO

Reproductive anomalies associated with the tsetse DNA virus infection in the female tsetse hosts, Glossina morsitans centralis Machado and Glossina morsitans morsitans Westwood, inoculated with the virus during the 3rd instar larval stage were studied and the data compared to those obtained from the control females injected with sterile physiological saline. Virus infected flies had significantly longer first and second pregnancy cycles (P<0.0001) and produced pupae that were of significantly less weight in miligrams (P<0.0001) compared to controls. Transmission of the virus to progeny was not absolute and only 21 per cent of G.m. centralis and 48 per cent of G.m. morsitans first progeny flies from infected females developed salivary gland hypertrophy as a result of transmission from mother to progeny. The virus infected females produced significantly fewere pupae compared to the controls during the experimental period (P<0.00001).


Assuntos
Animais , Infecções por Vírus de DNA , Reprodução/genética , Moscas Tsé-Tsé/virologia , Glossinidae/fisiologia
17.
Biochem Genet ; 35(1-2): 1-11, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9238514

RESUMO

Gene diversity was investigated in four taxa of tsetse flies (Diptera: Glossinidae) including Glossina morsitans, G.m. centralis, G. Swynnertoni, and G. pallidipes. Histochemical tests were performed for 35-46 isozymes. Polymorphic loci were 20% in G. morsitans, 32% in G.m. centralis, 17.6% in G. swynnertoni, and 26% in G. pallidipes. Mean heterozygosities among all loci were 6.6% in G. morsitans morsitans, 6.0% in G.m. centralis, 7.1% in G. swynnertoni, and 6.8% pallidipes. Allozyme gene diversities were considerably less than those reported for many Diptera. The low gene diversities are probably related to small effective population sizes.


Assuntos
Enzimas/genética , Variação Genética , Genética Populacional , Glossinidae/genética , Animais , Dípteros/genética , Eletroforese em Gel de Poliacrilamida , Heterozigoto , Polimorfismo Genético , Trealase/genética , Moscas Tsé-Tsé/genética
18.
Int J Radiat Biol ; 69(1): 67-74, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8601757

RESUMO

The effect of gamma-radiation doses ranging between 10 and 180 Gy on 4-6-day-old adult males of Glossina tachinoides, Glossina fuscipes fuscipes and Glossina brevipalpis was studied. Fecundity of their mates was reduced by 95% following exposure to 120, 80-100 and 50 Gy of adult male G. tachinoides, G. f. fuscipes and G. brevipalpis respectively. Insemination ability of the males and sperm motility were not adversely affected by the radiation treatment. The higher proportion of dominant lethals in the sperm of the three species with increasing radiation doses was reflected in the reproductive status of the female mates, i.e. an increasing percentage of females showing imbalances between intrauterine content and ovarian development (females with an empty uterus due to expulsion of a dead embryo after embryonic arrest or a degenerating egg in utero) and an acceleration in follicle development associated with successive unsuccessful cycles. In the F1 progeny of all treated groups, no significant bias of the sex ratio was found. The average life span of G. tachinoides and G. f. fuscipes males treated with doses of > or = 80 Gy and of G. brevipalpis males treated with doses >140 Gy was significantly reduced as compared with untreated controls. Male G. brevipalpis treated with doses ranging between 10 and 40 Gy, however, showed a significant radiation induced increase in average life span.


Assuntos
Raios gama , Glossinidae/efeitos da radiação , Tolerância a Radiação , Animais , Feminino , Fertilidade/efeitos da radiação , Glossinidae/fisiologia , Masculino , Reprodução/efeitos da radiação , Especificidade da Espécie
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