RESUMEN
The trematodes from South American reptiles are poorly known, with only one life cycle completely characterized. We used molecular and morphological methods to characterize diplostomoid metacercariae found in 29 of 86 pointedbelly frogs, Leptodactylus podicipinus (Cope, 1862) collected in a marsh pond in Selvíria, in the central-west region of Brazil. The metacercariae were identified as Heterodiplostomum lanceolatum Dubois, 1936 (Proterodiplostomidae), a rarely reported species that matures in snakes. In phylogenetic analysis of partial sequences from 28S rDNA, H. lanceolatum fell within a polytomy with the proterodiplostomid Crocodilicola pseudostoma (molecular divergence of 4.1%) and other members of the superfamily Diplostomoidea. Our collections provide insights into the ecology of this parasite, in that infected frogs were smaller than uninfected frogs, and metacercariae were more numerous in the abdominal cavity and hindlimb muscles than in abdominal muscles, which suggests directions for future research on the transmission and pathology of this proterodiplostomid.
Asunto(s)
Anuros/parasitología , Metacercarias/anatomía & histología , Trematodos/clasificación , Animales , Brasil , ADN Ribosómico/genética , Estadios del Ciclo de Vida , Metacercarias/aislamiento & purificación , Filogenia , ARN Ribosómico 28S/genética , Especificidad de la Especie , Trematodos/anatomía & histología , Trematodos/aislamiento & purificaciónRESUMEN
The phylogenetic position of Clinostomum heluans Braun, 1899 within the genus Clinostomum Leidy, 1856 is reported in this study based on sequences of the barcoding region of the mitochondrial cytochrome c oxidase subunit 1 gene ( COX1). Additionally, molecular data are used to link the adult and the metacercariae of the species. The metacercariae of C. heluans were found encysted infecting the cichlid fish Australoheros sp. in Minas Gerais, Brazil, whereas the adults were obtained from the mouth cavity of the Great White Egret, Ardea alba, in Campeche, Mexico. The COX1 sequences obtained for the Mexican clinostomes and the Brazilian metacercaria were almost identical (0.2% molecular divergence), indicating conspecificity. Similar molecular divergence (0.2-0.4%) was found between sequences of C. heluans reported here and Clinostomum sp. 6 previously obtained from a metacercaria recovered from the cichlid Cichlasoma boliviense in Santa Cruz, Bolivia. Both maximum likelihood and Bayesian inference analyses unequivocally showed the conspecificity between C. heluans and Clinostomum sp. 6, which form a monophyletic clade with high nodal support and very low genetic divergence. Moreover, tree topology reveals that C. heluans occupies a basal position with respect to New World species of Clinostomum, although a denser taxon sampling of species within the genus is further required. The metacercaria of C. heluans seems to be specific to cichlid fish because both samples from South America were recovered from species of this fish family, although not closely related.
Asunto(s)
Enfermedades de las Aves/parasitología , ADN de Helmintos/química , Enfermedades de los Peces/parasitología , Filogenia , Trematodos/clasificación , Infecciones por Trematodos/veterinaria , Animales , Secuencia de Bases , Aves , Brasil , Cíclidos/parasitología , Código de Barras del ADN Taxonómico/veterinaria , ADN de Helmintos/genética , Complejo IV de Transporte de Electrones/química , Complejo IV de Transporte de Electrones/genética , Metacercarias/clasificación , Metacercarias/genética , México , Mitocondrias/enzimología , Mitocondrias/genética , Trematodos/genética , Trematodos/crecimiento & desarrollo , Infecciones por Trematodos/parasitologíaRESUMEN
Paratanaisia bragai é um trematódeo que parasita rins e ureteres de aves domésticas e selvagens. Apesar de considerado pouco patogênico pode levar a complicações clínicas e morte em infecções severas. No presente estudo, um caso de parasitismo fatal em maritaca (Psittacara leucophthalmus) por P. bragai é relatado. A ave, oriunda da área urbana do município de Lavras, Minas Gerais, Brasil, teve manifestações clínicas de apatia, desidratação, dispneia e veio a óbito. Na necropsia foram observados rins aumentados de volume, pálidos, com superfície irregular e nodulações esbranquiçadas. Ao corte verificaram-se parasitos nos rins, que foram processados para montagem de lâminas permanentes e identificados segundo técnica de rotina como P. bragai. No exame histopatológico dos rins foram constatados infiltrado inflamatório linfoplasmocítico multifocal moderado, dilatação de túbulos e focos de regeneração tubular, associados a fibrose intersticial moderada no córtex renal. Na medula renal havia infiltrado de macrófagos, heterófilos, eosinófilos e células gigantes multinucleadas associado a parasitos em ductos coletores dilatados. O parasitismo de P. leucophthalmus por P. bragai é relatado pela primeira vez. A importância de se considerar este parasito entre as possibilidades diagnósticas em aves com insuficiência renal é brevemente discutida.(AU)
Paratanaisia bragai is a trematode parasite of the kidneys and ureters of poultry and wild birds. Despite its low pathogenicity, this parasite can lead to several clinical complications and death in heavy infections. In the present study, a fatal case of parasitism by P. bragai in a specimen of the White-eyed Parakeet, Psittacara leucophthalmus, is reported. The bird, coming from the urban area of the county of Lavras, Minas Gerais, Brazil, was clinically evaluated and revealed apathy, dehydration, dyspnea, and death. The gross findings were pale and enlarged kidneys, which also had irregular surface with whitish nodulations. Parasites were observed on cutting surface of the renal parenchyma. They were processed for assembly of permanent slides and identified as P. bragai according to routine technique. The histologic findings were mild multifocal lymphoplasmacytic infiltrate, tubular dilatation and foci of tubular regeneration related to mild interstitial fibrosis in the renal cortex, and infiltration of macrophages, heterophils, eosinophils and multinucleated giant cells associated with metazoan parasites in the collecting ducts in renal medulla. The parasitism of P. leucophthalmus by P. bragai is reported for the first time. The importance of considering this parasite among the diagnostic possibilities in birds with renal insufficiency is briefly discussed.(AU)
Asunto(s)
Técnicas de Laboratorio Clínico/veterinaria , Loros/parasitología , Infecciones por TrematodosRESUMEN
Paratanaisia bragai é um trematódeo que parasita rins e ureteres de aves domésticas e selvagens. Apesar de considerado pouco patogênico pode levar a complicações clínicas e morte em infecções severas. No presente estudo, um caso de parasitismo fatal em maritaca (Psittacara leucophthalmus) por P. bragai é relatado. A ave, oriunda da área urbana do município de Lavras, Minas Gerais, Brasil, teve manifestações clínicas de apatia, desidratação, dispneia e veio a óbito. Na necropsia foram observados rins aumentados de volume, pálidos, com superfície irregular e nodulações esbranquiçadas. Ao corte verificaram-se parasitos nos rins, que foram processados para montagem de lâminas permanentes e identificados segundo técnica de rotina como P. bragai. No exame histopatológico dos rins foram constatados infiltrado inflamatório linfoplasmocítico multifocal moderado, dilatação de túbulos e focos de regeneração tubular, associados a fibrose intersticial moderada no córtex renal. Na medula renal havia infiltrado de macrófagos, heterófilos, eosinófilos e células gigantes multinucleadas associado a parasitos em ductos coletores dilatados. O parasitismo de P. leucophthalmus por P. bragai é relatado pela primeira vez. A importância de se considerar este parasito entre as possibilidades diagnósticas em aves com insuficiência renal é brevemente discutida.(AU)
Paratanaisia bragai is a trematode parasite of the kidneys and ureters of poultry and wild birds. Despite its low pathogenicity, this parasite can lead to several clinical complications and death in heavy infections. In the present study, a fatal case of parasitism by P. bragai in a specimen of the White-eyed Parakeet, Psittacara leucophthalmus, is reported. The bird, coming from the urban area of the county of Lavras, Minas Gerais, Brazil, was clinically evaluated and revealed apathy, dehydration, dyspnea, and death. The gross findings were pale and enlarged kidneys, which also had irregular surface with whitish nodulations. Parasites were observed on cutting surface of the renal parenchyma. They were processed for assembly of permanent slides and identified as P. bragai according to routine technique. The histologic findings were mild multifocal lymphoplasmacytic infiltrate, tubular dilatation and foci of tubular regeneration related to mild interstitial fibrosis in the renal cortex, and infiltration of macrophages, heterophils, eosinophils and multinucleated giant cells associated with metazoan parasites in the collecting ducts in renal medulla. The parasitism of P. leucophthalmus by P. bragai is reported for the first time. The importance of considering this parasite among the diagnostic possibilities in birds with renal insufficiency is briefly discussed.(AU)
Asunto(s)
Técnicas de Laboratorio Clínico/veterinaria , Loros/parasitología , Infecciones por TrematodosRESUMEN
Pleurolophocercous cercariae found in the invasive gastropod Melanoides tuberculata (Müller, 1774) collected in a stream of the Vila do Abraمo, Ilha Grande, Angra dos Reis, Rio de Janeiro, Brazil were used for experimental infection that enabled the identification of the heterophyid trematode Centrocestus formosanus (Nishigori, 1924). The parasite has been found in the locality since 2007, after two years of the introduction of M. tuberculata. Recently, from a sample of 483 specimens collected in June 2013, 101 (21%) were found infected with parasite. The potential environmental impacts caused by the parasite occurrence could be underestimated in the country, and actions to monitor and control both the parasite and the mollusk are necessary.(AU)
Cercárias do tipo pleurolofocerca encontradas no gastrópode invasor Melanoides tuberculata (Müller, 1774) coletados em um riacho da Vila do Abraão em Ilha Grande, Angra dos Reis, Rio de Janeiro, Brasil foram utilizadas em estudos de infecção experimental que possibilitaram a identificação do trematódeo heterofiídeo Centrocestus formosanus (Nishigori, 1924). O parasito vem sendo encontrado na localidade desde 2007, dois anos após a introdução do molusco. Recentemente, de uma amostra de 483 espécimes coletados em junho de 2013, 101 (21%) apresentavam-se infectados pelo parasito. Os potenciais impactos ambientais ocasionados pela ocorrência deste parasito podem estar sendo subestimados no país, sendo necessárias ações visando o monitoramento e controle tanto do parasito quanto do molusco.(AU)
Asunto(s)
Animales , Heterophyidae/patogenicidad , Cercarias/fisiología , Caracoles/parasitología , Especies Introducidas , BrasilRESUMEN
Abstract Pleurolophocercous cercariae found in the invasive gastropod Melanoides tuberculata (Müller, 1774) collected in a stream of the Vila do Abraão, Ilha Grande, Angra dos Reis, Rio de Janeiro, Brazil were used for experimental infection that enabled the identification of the heterophyid trematode Centrocestus formosanus (Nishigori, 1924). The parasite has been found in the locality since 2007, after two years of the introduction of M. tuberculata. Recently, from a sample of 483 specimens collected in June 2013, 101 (21%) were found infected with parasite. The potential environmental impacts caused by the parasite occurrence could be underestimated in the country, and actions to monitor and control both the parasite and the mollusk are necessary.
Resumo Cercárias do tipo pleurolofocerca encontradas no gastrópode invasor Melanoides tuberculata (Müller, 1774) coletados em um riacho da Vila do Abraão em Ilha Grande, Angra dos Reis, Rio de Janeiro, Brasil foram utilizadas em estudos de infecção experimental que possibilitaram a identificação do trematódeo heterofiídeo Centrocestus formosanus (Nishigori, 1924). O parasito vem sendo encontrado na localidade desde 2007, dois anos após a introdução do molusco. Recentemente, de uma amostra de 483 espécimes coletados em junho de 2013, 101 (21%) apresentavam-se infectados pelo parasito. Os potenciais impactos ambientais ocasionados pela ocorrência deste parasito podem estar sendo subestimados no país, sendo necessárias ações visando o monitoramento e controle tanto do parasito quanto do molusco.
Asunto(s)
Animales , Caracoles/parasitología , Heterophyidae/fisiología , Interacciones Huésped-Parásitos , Brasil , Especies Introducidas , Metacercarias/crecimiento & desarrollo , Metacercarias/fisiología , Heterophyidae/crecimiento & desarrolloRESUMEN
Pleurolophocercous cercariae found in the invasive gastropod Melanoides tuberculata (Müller, 1774) collected in a stream of the Vila do Abraão, Ilha Grande, Angra dos Reis, Rio de Janeiro, Brazil were used for experimental infection that enabled the identification of the heterophyid trematode Centrocestus formosanus (Nishigori, 1924). The parasite has been found in the locality since 2007, after two years of the introduction of M. tuberculata. Recently, from a sample of 483 specimens collected in June 2013, 101 (21%) were found infected with parasite. The potential environmental impacts caused by the parasite occurrence could be underestimated in the country, and actions to monitor and control both the parasite and the mollusk are necessary.
Asunto(s)
Heterophyidae/fisiología , Interacciones Huésped-Parásitos , Caracoles/parasitología , Animales , Brasil , Heterophyidae/crecimiento & desarrollo , Especies Introducidas , Metacercarias/crecimiento & desarrollo , Metacercarias/fisiologíaRESUMEN
The importance of platynosomiasis has increased in feline veterinary practice, but aspects related to the specificity of Platynosomum spp. in definitive hosts requires further study. Although morphological traits suggest that the same species, P. illiciens, may infect both birds and mammals, the synonymies previously proposed have not been widely accepted, likely because host specificity is assumed. In addition, the name P. fastosum has frequently been used for parasites recovered from mammals. In the present study, metacercariae (n= 100/animal) of P. illiciens recovered from lizards (Hemidactylus mabouia) in Brazil were fed to Australian parakeets (Melopsittacus undulatus) and mice. Two parasites were recovered from the liver of one M. undulatus specimen during a necropsy that was performed 105 days after infection, and all mice were found to be infected with 37 ± 12 (18-48) parasites. The morphology of the P. illiciens obtained from the parakeet was similar to that of parasites obtained from mice and those described previously from naturally infected birds and mammals. Non-specificity of P. illiciens in hosts is discussed briefly, based on the parasitological and morphological results obtained during the avian experimental platynosomiasis and the epidemiology and geographical distribution of this parasite.
Asunto(s)
Dicrocoeliidae/crecimiento & desarrollo , Especificidad del Huésped , Infecciones por Trematodos/veterinaria , Animales , Aves , Brasil , Dicrocoeliidae/aislamiento & purificación , Lagartos , Mamíferos , Ratones , Infecciones por Trematodos/parasitologíaRESUMEN
Despite the large number of reports of species of Clinostomum from vertebrate hosts in South America, studies evaluating the molluscan transmitters of these parasites are scarce. In the present study, clinostomatoid cercariae shed from 0.02% (4/17,485) specimens of Biomphalaria spp., collected at the Pampulha reservoir, Belo Horizonte, Minas Gerais, Brazil, were used for experimental infection of Poecilia reticulata . Samples of cercariae from molluscs and metacercariae experimentally obtained from fish were subjected to morphological and molecular analyses and compared with species of Clinostomum reported in the Americas. The cercariae and metacercariae, here identified as Clinostomum sp., present general morphology similar to that reported for Clinostomum marginatum , however, from molecular point of view, differ significantly from North American C. marginatum and other species of Clinostomum reported in South America. These results suggest that the diversity of Clinostomum found in Brazil may be underestimated. Additional studies aimed at molecular characterization of South American species of Clinostomum, including the finding of specimens with sequences similar to that reported for C. marginatum in North America are required.
Asunto(s)
Biomphalaria/parasitología , Enfermedades de los Peces/parasitología , Poecilia/parasitología , Trematodos/fisiología , Infecciones por Trematodos/veterinaria , Animales , Brasil , ADN de Helmintos/química , ADN Mitocondrial/química , ADN Ribosómico/química , ADN Espaciador Ribosómico/genética , Complejo IV de Transporte de Electrones/genética , Femenino , Enfermedades de los Peces/transmisión , Agua Dulce , Humanos , Funciones de Verosimilitud , Datos de Secuencia Molecular , Filogenia , Alineación de Secuencia , Trematodos/anatomía & histología , Trematodos/clasificación , Trematodos/genética , Infecciones por Trematodos/parasitología , Infecciones por Trematodos/transmisiónRESUMEN
Intensification of Brazilian cattle ranching systems has attracted both national and international attention due to its direct relation with Amazon deforestation on the one hand and increasing demand of the global population for meat on the other. Since Brazilian cattle ranching is predominantly pasture-based, we particularly focus on pasture management. We summarize the most recurrent opportunities and risks associated with pasture intensification that are brought up within scientific and political dialogues, and discuss them within the Brazilian context. We argue that sustainable intensification of pasturelands in Brazil is a viable way to increase agricultural output while simultaneously sparing land for nature. Since environmental degradation is often associated with low-yield extensive systems in Brazil, it is possible to obtain higher yields, while reversing degradation, by adopting practices like rotational grazing, incorporation of legumes and integrated crop-livestock-forestry systems. Technical assistance is however essential, particularly for small- and medium-scale farmers. Sound complementary policies and good governance must accompany these measures so that a 'rebound effect' does not lead to increased deforestation and other adverse social and environmental impacts. It is also important that animal welfare is not compromised. Although the discussion is presented with respect to Brazil, some aspects are relevant to other developing countries.
Asunto(s)
Crianza de Animales Domésticos/economía , Crianza de Animales Domésticos/métodos , Bovinos/fisiología , Ambiente , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Brasil , Conservación de los Recursos Naturales/métodos , Riesgo , Factores SocioeconómicosRESUMEN
Species of Ribeiroia are trematode parasites of birds and mammals that have acquired notoriety since Ribeiroia ondatrae was identified as a cause of mortality and malformations in North American amphibians. Although species of Ribeiroia have been reported in vertebrate hosts in South America, the snails involved in its transmission remain unknown in Brazil. During malacological studies conducted at Pampulha Reservoir, Belo Horizonte, Minas Gerais, Brazil, between January 2009 and February 2012, in total 14,264 specimens of Biomphalaria straminea were collected, of which 192 (1.35%) were infected with gymnocephalous cercariae. The larvae were used for experimental infection of laboratory-reared guppies ( Poecilia reticulata ); metacercariae obtained in these fishes were orally administered to domestic ducks (Cairina moschata); and adult parasites were obtained from the proventriculus 10 days after infection. Based on morphological and molecular analyses, the parasite was identified as Ribeiroia sp., a species morphologically similar to R. ondatrae , but distinctly different at the molecular level. This is the first report of larvae of Ribeiroia in Brazil and B. straminea as a new intermediate host for this genus.
Asunto(s)
Biomphalaria/parasitología , Trematodos/fisiología , Infecciones por Trematodos/transmisión , Animales , Brasil , Vectores de Enfermedades , Patos , PoeciliaRESUMEN
Austrodiplostomum compactum has been involved in cases of ocular diplostomiasis in several species of fish in Brazil, but the molluscan intermediate hosts of the parasite remain unknown. In the present study, malacological surveys were carried out at Pampulha Reservoir, Belo Horizonte, Minas Gerais, Brazil, between January 2009 and July 2012. A total of 16,119 specimens of Biomphalaria spp. were collected and examined, of which 68/14,948 specimens (0.45%) of Biomphalaria straminea and 6/541 (1.11%) of Biomphalaria glabrata were found harboring a strigeid cercariae. Groups of 5 specimens of Cyprinius carpio were experimentally infected with these cercariae (100 larvae/fish), and metacercariae were recovered from the eyes of the fish, 65 days after infection, with a mean intensity of infection of 10.4 (8-13) metacercariae/fish. Morphological study on cercariae and metacercariae identified them as A. compactum . This is the first record of cercariae of A. compactum in Brazil, and B. straminea and B. glabrata as new intermediate hosts for the parasite.
Asunto(s)
Biomphalaria/parasitología , Vectores de Enfermedades , Infecciones Parasitarias del Ojo/veterinaria , Enfermedades de los Peces/transmisión , Trematodos/fisiología , Infecciones por Trematodos/veterinaria , Animales , Biomphalaria/clasificación , Brasil/epidemiología , Carpas/parasitología , Vectores de Enfermedades/clasificación , Ojo/parasitología , Infecciones Parasitarias del Ojo/parasitología , Infecciones Parasitarias del Ojo/transmisión , Enfermedades de los Peces/epidemiología , Enfermedades de los Peces/parasitología , Lagos , Trematodos/clasificación , Trematodos/aislamiento & purificación , Infecciones por Trematodos/parasitología , Infecciones por Trematodos/transmisiónRESUMEN
Melanoides tuberculata , naturally infected by gymnocephalous cercariae, were found in aquatic collections from Belo Horizonte, Minas Gerais, Brazil. After morphological characterization, larvae were used for experimental infection of Poecilia reticulata. Metacercariae were obtained from the liver of these fish, which were also found to be naturally infected in the same locality. The morphology and biology of the developmental stages of trematodes we obtained were characteristic of Renicola sp. This is the first record of renicolid cercariae and metacercariae in Brazil.
Asunto(s)
Gastrópodos/parasitología , Trematodos/aislamiento & purificación , Animales , Brasil/epidemiología , Cercarias/aislamiento & purificación , Enfermedades de los Peces/epidemiología , Enfermedades de los Peces/parasitología , Estadios del Ciclo de Vida , Hígado/parasitología , Masculino , Metacercarias/aislamiento & purificación , Oocistos/clasificación , Poecilia/parasitología , Prevalencia , Trematodos/clasificación , Trematodos/crecimiento & desarrollo , Infecciones por Trematodos/epidemiología , Infecciones por Trematodos/parasitología , Infecciones por Trematodos/veterinariaRESUMEN
Bidens sulphurea (synonym Cosmos sulphureus) (Asteraceae), commonly known as yellow cosmos, is a native herbaceous species from Mexico that is widely used as an ornamental. It has been introduced in Brazil and has escaped from gardens, becoming a minor weed in ruderal, crop and pasture areas (2). In June 2010, groups of B. sulphurea individuals were found in a garden at the locality of Piúna, municipality of Viçosa (state of Minas Gerais, Brazil), that were severely attacked by gray mold. The disease led to flower rot with dieback of infected peduncles and stems. Plant tissues became brown to grayish brown and were covered by extensive fungal sporulation; in addition, seeds were colonized and destroyed by the fungus. A hyphomycete was regularly found associated with the diseased flowers, which was readily recognized as having a morphology typical of Botrytis cinerea: conidiophores solitary, cylindrical, terminally branched, 15 to 20 µm wide, grayish to olivaceous gray, and smooth; conidiogenous cells polyblastic, subcylindrical to ampulliform, and 120 to 230 × (13-) 14 to 16 (-19) µm; conidia ellipsoid to obovoid, 8 to 12 × 6.5 to 8 (-9) µm, with a discrete hilum at the base, 1 to 2 µm, aseptate, and hyaline. The fungus was isolated in pure culture and inoculation of one isolate on healthy B. suphurea individuals was carried out with a 2.14 × 106 conidia/ml suspension, which was sprayed to runoff onto three plants bearing four to six inflorescences. All plants were left in a moist chamber for 48 h and later transferred to a bench in a greenhouse at 21 ± 3°C. Gray mold symptoms appeared after 10 days that led to rapid and complete necrosis of flowers and peduncles. Infection first appeared on the flowers but progressed downward, leading to top dieback and finally plant death (not seen in the field). Only Botrytis cinerea was obtained in isolations from diseased flowers, demonstrating the pathogenicity of the fungus. A representative sample was deposited in the UFV herbarium (VIC 31602). The only other record of Botrytis cinerea causing gray mold of B. sulphurea is from China (1,3). To our knowledge, this is the first record of Botrytis cinerea causing gray mold on B. sulphurea in Brazil. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Botany and Mycology Laboratory, ARS, UDSA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , 2011. (2) H. Lorenzi and H. M. Souza. Plantas Ornamentais no Brasil. Plantarum, Nova Odessa, Brazil. 1995. (3) Z. Zhang. Flora Fungorum Sinicorum. Vol. 26. Botrytis, Ramularia. Science Press, Beijing, China. 2006.
Asunto(s)
Altitud , Antígenos Dermatofagoides/inmunología , Polvo/análisis , Hipersensibilidad/inmunología , Pyroglyphidae/inmunología , Animales , Antígenos Dermatofagoides/metabolismo , Polvo/inmunología , Ecosistema , Ecuador , Humanos , Hipersensibilidad/epidemiología , Hipersensibilidad/parasitología , Estadios del Ciclo de Vida , Salud Pública , Pyroglyphidae/crecimiento & desarrollo , Refugiados , Erupciones VolcánicasAsunto(s)
Antígenos Dermatofagoides/efectos adversos , Asma/inmunología , Dermatophagoides pteronyssinus/inmunología , Proteínas de Insectos/efectos adversos , Rinitis/inmunología , Adolescente , Adulto , Alérgenos/administración & dosificación , Alérgenos/efectos adversos , Animales , Antígenos Dermatofagoides/administración & dosificación , Pruebas de Provocación Bronquial , Niño , Preescolar , Exposición a Riesgos Ambientales/efectos adversos , Humanos , Inmunización , Proteínas de Insectos/administración & dosificación , Factores de Riesgo , Pruebas CutáneasRESUMEN
There are no reports to date of entire gene sequences coding for chitinolytic enzymes from entomopathogenic fungi, even though these enzymes act synergistically with proteolytic enzymes to solubilize insect cuticle during the key step of host penetration, having considerable importance in the biological control of some insect pests. This paper reports the complete nucleotide sequence and analysis of the chromosomal and full-length cDNA copies of the regulated gene (chit1) coding one of the chitinases produced by the biocontrol agent Metarhizium anisopliae. Degenerated primers, encompassing conserved regions of other fungal chitinases, were used to amplify a 650-bp DNA fragment, which was used to isolate genomic and cDNA clones from M. anisopliae. Albeit at least two different chitinases are characterized in this fungus, only one chit gene was isolated. The chit1 gene is interrupted by three short typical fungal introns and has a 1,521-bp ORF, which encodes a protein of 423 amino acids with a stretch of 35 amino acid residues displaying characteristics of signal peptide. The deduced sequence of the mature protein predicts a 42-kDa protein with pI of 5.8. Southern analysis of genomic DNA indicates a single copy of chit1 in the M. anisopliae genome.
Asunto(s)
Quitinasas/genética , ADN de Hongos/genética , ADN de Hongos/aislamiento & purificación , Genes Fúngicos , Hongos Mitospóricos/enzimología , Hongos Mitospóricos/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Dominio Catalítico/genética , Clonación Molecular , ADN Complementario/genética , ADN Complementario/aislamiento & purificación , Genoma Fúngico , Insectos/microbiología , Hongos Mitospóricos/patogenicidad , Datos de Secuencia Molecular , Sistemas de Lectura AbiertaRESUMEN
Due to the physiological importance of its product, the Cu/Zn superoxide dismutase enzyme, the gene coding for this enzyme was mapped in five species of the Drosophila willistoni subgroup and in D. nebulosa by in situ hybridization using D. melanogaster as a control. The results indicate that this locus is located on the XR chromosomal arm of the five sibling species and on the XL chromosomal arm of D. nebulosa, suggesting the occurrence of a pericentric inversion before the separation of these entities.