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1.
Braz J Biol ; 81(4): 1144-1165, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33111929

RESUMEN

Although currently there is already a set of studies regarding ecological aspects of some particular reptile and amphibian species living in Brazilian sandy coastal plains (including the so-called "restinga" and "campo nativo" habitats), there is comparatively few information on the species composition usually associated to these environments. During 31 years (1988-2019) of herpetological studies carried out in sandy coastal plains environments by our research team of the Laboratory of Vertebrate Ecology (Department of Ecology, Universidade do Estado do Rio de Janeiro, in Rio de Janeiro Brazil) we have surveyed reptile and amphibian communities and performed different studies with similar methods in 70 sites from 10 different states along the Brazilian coast. Our surveys resulted in records of 87 species of reptile (five turtles, two crocodylians, six amphisbaenians, 36 lizards and 39 snakes) from 24 families, and 77 species of anuran amphibians from nine families. We have studied multiple natural history topics for anurans and reptiles which resulted in the publication of some specific ecological studies, especially regarding some species, encompassing population and community ecology, foraging and feeding habits, species activity, thermoregulation, reproduction, use of microhabitats, and parasitism by ecto and endoparasites. Our results along these three decades have also contributed for the description of four new lizard species (Ameivula nativo, Glaucomastix littoralis, G. abaetensis and G. itabaianensis). Our studies constitute an important contribution to the knowledge of the ecology of anuran amphibians and reptiles in these ecosystems, as well as to the conservation of sandy coastal plains environment. The checklist presented in this study, based on our records of sandy coastal plains herpetofauna, provides for many localities along the Brazilian coast, the needed knowledge on species occurrence, including the presence of endemic and/or endangered species, which can be of value for many conservation actions.


Asunto(s)
Ecosistema , Lagartos , Animales , Anuros , Brasil , Arena
2.
J Exp Bot ; 59(10): 2875-90, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18552354

RESUMEN

In tomato, numerous wild-related species have been demonstrated to be untapped sources of valuable genetic variability, including pathogen-resistance genes, nutritional, and industrial quality traits. From a collection of S. pennellii introgressed lines, 889 fruit metabolic loci (QML) and 326 yield-associated loci (YAL), distributed across the tomato genome, had been identified previously. By using a combination of molecular marker sequence analysis, PCR amplification and sequencing, analysis of allelic variation, and evaluation of co-response between gene expression and metabolite composition traits, the present report, provides a comprehensive list of candidate genes co-localizing with a subset of 106 QML and 20 YAL associated either with important agronomic or nutritional characteristics. This combined strategy allowed the identification and analysis of 127 candidate genes located in 16 regions of the tomato genome. Eighty-five genes were cloned and partially sequenced, totalling 45,816 and 45,787 bases from S. lycopersicum and S. pennellii, respectively. Allelic variation at the amino acid level was confirmed for 37 of these candidates. Furthermore, out of the 127 gene-metabolite co-locations, some 56 were recovered following correlation of parallel transcript and metabolite profiling. Results obtained here represent the initial steps in the integration of genetic, genomic, and expressional patterns of genes co-localizing with chemical compositional traits of the tomato fruit.


Asunto(s)
Proteínas de Plantas/genética , Sitios de Carácter Cuantitativo , Solanum lycopersicum/genética , Clonación Molecular , Frutas/química , Frutas/genética , Frutas/metabolismo , Expresión Génica , Regulación de la Expresión Génica de las Plantas , Genoma de Planta , Solanum lycopersicum/química , Solanum lycopersicum/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo
3.
Dis Aquat Organ ; 81(2): 93-7, 2008 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-18924373

RESUMEN

Chytridiomycosis, caused by the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd), is an emerging infectious disease responsible for amphibian declines on several continents. In laboratory conditions, optimal temperatures for Bd growth and survivorship are between 17 and 25 degrees C. We investigated the effect of different storage temperatures, both in field and laboratory conditions, on detection of Bd from swabs stored for 7 d. We sampled 52 wild Litoria wilcoxii males for Bd by simultaneously running 2 cotton swabs along the skin of the frog. One group of swabs was stored in a freezer within 2 h of sampling and the other was kept in a car in an exposed environment for 7 d before being stored in the freezer. In the laboratory experiment, swabs were inoculated with zoospores of Bd and underwent one of 4 treatments: immediate DNA extraction, or storage at 27, 38 or 45 degrees C for 7 d prior to DNA extraction. Swabs from all treatments were analyzed by quantitative (real-time) PCR test. Though prevalence of Bd did not differ significantly between swabs that were frozen and those that remained in a car for 7 d (19.2 vs. 17.3%, respectively), the number of Bd zoospores detected on car swabs taken from infected frogs was, on average, 67% less than that detected on the corresponding frozen swab. In the laboratory experiment, the number of zoospore equivalents varied significantly with treatment (F(3,35) = 4.769, p = 0.007), indicating that there was reduced recovery of Bd DNA from swabs stored at higher temperatures compared with those stored at lower temperatures or processed immediately. We conclude that failure to store swabs in cool conditions can result in a significant reduction in the amount of Bd DNA detected using the PCR assay. Our results have important implications for researchers conducting field sampling of amphibians for Bd.


Asunto(s)
Anuros/microbiología , Quitridiomicetos/fisiología , ADN de Hongos/química , Calor , Reacción en Cadena de la Polimerasa , Manejo de Especímenes , Animales , Masculino
4.
Parasite ; 15(2): 131-6, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18642505

RESUMEN

We studied the parasitism by the chigger mite Eutrombicula alfreddugesi on four sympatric lizard species of the genus Tropidurus in Morro do Chapéu, Bahia state, Brazil: T. hispidus, T. cocorobensis, T. semitaeniatus and T. erythrocephalus. For each species, we investigated the patterns of infestation and analyzed to which extent they varied among the hosts. We calculated the spatial niche breadth of the chigger mite on the body of each host species and the distribution of mites along the hosts' bodies for each Tropidurus species. All four species of Tropidurus at Morro do Chapéu were parasited by the chigger mite, with high (97-100%) prevalences. Host body size significantly explained the intensity of mite infestation for all species, except T. erythrocephalus. The body regions with highest intensity of infestation in the four lizard species were the mite pockets. The spacial niche width of the chigger varied consistently among the four lizards species studied being highest for T. erytrocephalus and lowest for T. cocorobensis. We conclude that the distribution and intensity with which lizards of the genus Tropidurus are infested by Eutrombicula alfreddugesi larvae results from the interaction between aspects of host morphology (such as body size and the occurrence and distribution of mite pockets) and ecology (especially microhabitat use).


Asunto(s)
Interacciones Huésped-Parásitos , Lagartos/parasitología , Trombiculiasis/veterinaria , Trombiculidae/parasitología , Animales , Brasil/epidemiología , Lagartos/anatomía & histología , Prevalencia , Especificidad de la Especie , Trombiculiasis/epidemiología , Trombiculiasis/parasitología
5.
Braz J Biol ; 68(1): 101-7, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18470383

RESUMEN

We studied the species richness and composition of frogs in 10 restinga habitats (sand dune environments dominated by herbaceous and shrubby vegetation) along approximately 1500 km of coastal areas of three Brazilian States: Rio de Janeiro (Grumari, Maricá, Massambaba, Jurubatiba and Grussaí), Espírito Santo (Praia das Neves and Setiba) and Bahia (Prado and Trancoso). We estimated beta-diversity and similarity among areas and related these parameters to geographic distance between areas. All areas were surveyed with a similar sampling procedure. We found 28 frog species belonging to the families Hylidae, Microhylidae, Leptodactylidae and Bufonidae. Frogs in restingas were in general nocturnal with no strictly diurnal species. The richest restinga was Praia das Neves (13 species), followed by Grussaí and Trancoso (eight species in each). The commonest species in the restingas was Scinax alter (found in eight restingas), followed by Aparasphenodon brunoi (seven areas). Our data shows that richness and composition of frog communities vary consistently along the eastern Brazilian coast and, in part, the rate of species turnover is affected by the distance among areas. Geographic distance explained approximately 12% of species turnover in restingas and about 9.5% of similarity among frog assemblages. Although geographic distance somewhat affects frog assemblages, other factors (e.g. historical factors, disturbances) seem to be also involved in explaining present frog assemblage composition in each area and species turnover among areas. The frog fauna along restinga habitats was significantly nested (matrix community temperature = 26.13 degrees; p = 0.007). Our data also showed that the most hospitable restinga was Praia das Neves and indicated that this area should be protected as a conservation unit. Frog assemblage of each area seems to partially represent a nested subset of the original assemblage, although we should not ignore the importance of historical factors. This nestedness pattern, in part, probably results from the intensive fragmentation of restinga habitats. Possibly, many frog species may have been lost in some studied areas as a result of the extensive habitat degradation to which restinga habitats are presently exposed.


Asunto(s)
Anuros/clasificación , Biodiversidad , Animales , Brasil , Densidad de Población
6.
Parasite ; 14(2): 107-12, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17645181

RESUMEN

We studied some parameters of the parasitism by the mite Hannemonia sp. on the endemic frog Hylodes phyllodes in the Atlantic Forest of Ilha Grande (Rio de Janeiro State, Brazil). Prevalence, mean abundance, mean intensity and total intensity of infestation, body regions infected, and host sexual differences in parasitism rate of the larvae of Hannemania sp. on individuals of H. phyllodes were assessed. Prevalence was 86.5% (N = 37; total of 1,745 larvae of Hannemania sp) for male hosts and 91.7% (N = 12; total of 330 larvae) for female hosts, with no significant difference between the sexes. Overall prevalence of Hannemania sp. on H. phyllodes was 87.7%. Mean intensity of infestation in males (54.5 +/- 42.5; range 1-173 larvae) was higher than in females (29.9 +/- 47.6; range 1-166). We conclude that the rates of intensity, abundance, and prevalence of Hannemania larvae parasitizing Hylodes phyllodes at Ilha Grande were considerably high, suggesting that this species of anuran constitutes a relevant host for this mite species to complete its life-cycle in the area. Differences between males and females in infestation rates probably reflect their differential use of space in the forest.


Asunto(s)
Anuros/parasitología , Interacciones Huésped-Parásitos , Infestaciones por Ácaros/veterinaria , Ácaros , Animales , Brasil/epidemiología , Ecosistema , Femenino , Larva , Masculino , Infestaciones por Ácaros/epidemiología , Densidad de Población , Dinámica Poblacional , Prevalencia , Factores Sexuales , Especificidad de la Especie
7.
Braz J Biol ; 67(2): 263-73, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17876436

RESUMEN

"Restingas" (herbaceous/shrubby coastal sand-dune habitats) used to cover most of Rio de Janeiro State coast, and have suffered extensive degradation over the last five centuries. Using satellite images and field work, we identified the remaining restingas in the State, recording the factors that might cause their degradation. We used two mosaics of Landsat 7 scenes (spatial resolution 15 and 30 m) to map and evaluate preliminarly the remaining areas and conservation status. Each remnant area was checked in the field, degraded areas within it were mapped and subtracted from the remnants. We identified 21 restinga remnants totalling 105,285 ha. The largest and smallest restinga remnants were Jurubatiba (25,141 ha) and Itaipu (23 ha), respectively. We identified 14 causes of degradation. The most important were vegetation removal for housing developments, establishment of exotic plant species, change of original substrate, and selective removal of species of economic importance for the horticultural industry. All restingas had disturbed parts under strong pressure due to human activities. Due to intense habitat loss, and occurrence of endemic/threatened vertebrate species in restinga habitats, we strongly indicate the implementation of new conservation units to protect these fragile remnants. This habitat is steadily decreasing and most remnants lack legal protection. Therefore, under the current human pressure most of this unique habitat is likely to be lost from the State within the next few years.


Asunto(s)
Ecosistema , Monitoreo del Ambiente , Árboles , Brasil , Densidad de Población , Factores de Riesgo , Comunicaciones por Satélite
8.
Annu Rev Phytopathol ; 40: 169-89, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12147758

RESUMEN

This review deals with a comparative analysis of seven genome sequences from plant-associated bacteria. These are the genomes of Agrobacterium tumefaciens, Mesorhizobium loti, Sinorhizobium meliloti, Xanthomonas campestris pv campestris, Xanthomonas axonopodis pv citri, Xylella fastidiosa, and Ralstonia solanacearum. Genome structure and the metabolism pathways available highlight the compromise between the genome size and lifestyle. Despite the recognized importance of the type III secretion system in controlling host compatibility, its presence is not universal in all necrogenic pathogens. Hemolysins, hemagglutinins, and some adhesins, previously reported only for mammalian pathogens, are present in most organisms discussed. Different numbers and combinations of cell wall degrading enzymes and genes to overcome the oxidative burst generally induced by the plant host are characterized in these genomes. A total of 19 genes not involved in housekeeping functions were found common to all these bacteria.


Asunto(s)
Bacterias/genética , Genoma Bacteriano , Enfermedades de las Plantas/microbiología , Plantas/microbiología , Adaptación Fisiológica/genética , Bacterias/crecimiento & desarrollo , Adhesión Bacteriana/genética , Adhesión Bacteriana/fisiología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Extensiones de la Superficie Celular/genética , Extensiones de la Superficie Celular/fisiología , ADN Bacteriano/genética , ADN Bacteriano/metabolismo , Filogenia
9.
Braz J Biol ; 66(1A): 167-73, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16680312

RESUMEN

We analyzed the diet composition, endoparasites and sexual size dimorphism of the microhylid frog Chiasmocleis capixaba (Microhylidae) from a "mussununga" habitat in the municipality of Nova Viçosa, southern Bahia state, Brazil. All the 119 specimens analyzed were collected in a single night of heavy rainfall. Females (mean snout-vent length = 15.7 + 3.0 mm) were significantly larger than males (mean snout-vent length = 13.2 + 2.1 mm), and specimens of both sexes were smaller than those of a conspecific population previously reported in Aracruz, state of Espírito Santo state. The diet of C. capixaba was dominated by mites, ants and collembolans. Seventy-nine frogs (66.4% of the total) were infected by helminths, all belonging to a single species, Cosmocerca ornata, an intestinal nematode parasite.


Asunto(s)
Anuros , Tamaño Corporal , Conducta Alimentaria , Caracteres Sexuales , Animales , Anuros/anatomía & histología , Anuros/parasitología , Anuros/fisiología , Brasil , Femenino , Contenido Digestivo , Masculino , Árboles
10.
Braz. j. biol ; 81(4): 1144-1165, Oct.-Dec. 2021. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1153445

RESUMEN

Abstract Although currently there is already a set of studies regarding ecological aspects of some particular reptile and amphibian species living in Brazilian sandy coastal plains (including the so-called "restinga" and "campo nativo" habitats), there is comparatively few information on the species composition usually associated to these environments. During 31 years (1988-2019) of herpetological studies carried out in sandy coastal plains environments by our research team of the Laboratory of Vertebrate Ecology (Department of Ecology, Universidade do Estado do Rio de Janeiro, in Rio de Janeiro Brazil) we have surveyed reptile and amphibian communities and performed different studies with similar methods in 70 sites from 10 different states along the Brazilian coast. Our surveys resulted in records of 87 species of reptile (five turtles, two crocodylians, six amphisbaenians, 36 lizards and 39 snakes) from 24 families, and 77 species of anuran amphibians from nine families. We have studied multiple natural history topics for anurans and reptiles which resulted in the publication of some specific ecological studies, especially regarding some species, encompassing population and community ecology, foraging and feeding habits, species activity, thermoregulation, reproduction, use of microhabitats, and parasitism by ecto and endoparasites. Our results along these three decades have also contributed for the description of four new lizard species (Ameivula nativo, Glaucomastix littoralis, G. abaetensis and G. itabaianensis). Our studies constitute an important contribution to the knowledge of the ecology of anuran amphibians and reptiles in these ecosystems, as well as to the conservation of sandy coastal plains environment. The checklist presented in this study, based on our records of sandy coastal plains herpetofauna, provides for many localities along the Brazilian coast, the needed knowledge on species occurrence, including the presence of endemic and/or endangered species, which can be of value for many conservation actions.


Resumo Embora atualmente exista um conjunto de estudos sobre aspectos ecológicos de algumas espécies de répteis e de anfíbios que ocorrem nas planícies costeiras arenosas brasileiras (incluindo os chamados habitats de "restinga" e de "campo nativo"), há relativamente poucas informações sobre a composição de espécies geralmente associada a esses ambientes. Durante 31 anos (1988-2019) de estudos herpetológicos realizados em restingas por nossa equipe de pesquisa do Laboratório de Ecologia de Vertebrados (Departamento de Ecologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brasil) nós estudamos comunidades de répteis e de anfíbios e realizamos diferentes estudos com métodos semelhantes em 70 localidades de dez diferentes Estados ao longo da costa brasileira. Nossas pesquisas resultaram em registros de 87 espécies de répteis (cinco tartarugas, dois crocodilianos, seis anfisbênios, 36 lagartos e 39 serpentes) de 24 famílias, e 77 espécies de anfíbios anuros de nove famílias. Estudamos vários tópicos de história natural sobre anuros e répteis, que resultaram na publicação de alguns estudos ecológicos específicos, especialmente em relação a algumas espécies, abrangendo ecologia populacional e de comunidades, forrageamento e dieta, horário de atividade de espécies, termorregulação, reprodução, uso do microhabitat e parasitismo por ecto e endoparasitas. Nossos resultados ao longo dessas três décadas também contribuíram para a descrição de quatro novas espécies de lagartos (Ameivula nativo, Glaucomastix littoralis, G. abaetensis e G. itabaianensis). Nossos estudos constituem uma importante contribuição para o conhecimento da ecologia de répteis e de anfíbios anuros nesses ecossistemas, bem como para a conservação dos ecossistemas de restinga. A lista de espécies apresentada neste estudo, com base em nossos registros de herpetofauna das planícies costeiras arenosas, fornece para muitas localidades ao longo da costa brasileira o conhecimento necessário sobre a ocorrência de espécies, incluindo a presença de espécies endêmicas e/ ou ameaçadas de extinção, que podem ser úteis para muitas ações de conservação.


Asunto(s)
Animales , Ecosistema , Lagartos , Anuros , Brasil , Arena
11.
Cytogenet Genome Res ; 110(1-4): 229-41, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16093677

RESUMEN

Tnt1 elements are a superfamily of LTR-retrotransposons distributed in the Solanaceae plant family and represent good model systems for studying regulatory and evolutionary controls established between hosts and transposable elements. Tnt1 retrotransposons tightly control their activation, by restricting expression to specific conditions. The Tnt1A element, originally discovered in tobacco, is expressed in response to stress, and its activation by microbial factors is followed by amplification, demonstrating that factors of pathogen origin can generate genetic diversity in plants. The Tnt1A promoter has the potential to be activated by various biotic and abiotic stimuli but a number of these are specifically repressed in tobacco and are revealed only when the LTR promoter is placed in a heterologous context. We propose that a tobacco- and stimulus-specific repression has been established in order to minimize activation in conditions that might generate germinal transposition. In addition to tight transcriptional controls, Tnt1A retrotransposons self-regulate their activity through gradual generation of defective copies that have reduced transcriptional activity. Tnt1 retrotransposons found in various Solanaceae species are characterized by a high level of variability in the LTR sequences involved in transcription, and have evolved by gaining new expression patterns, mostly associated with responses to diverse stress conditions. Tnt1A insertions associated with genic regions are initially favored but seem subsequently counter-selected, while insertions in repetitive DNA are maintained. On the other hand, amplification and loss of insertions may result from more brutal occurrences, as suggested by the large restructuring of Tnt1 populations observed in tobacco compared to each of its parental species. The distribution of Tnt1 elements thus appears as a dynamic flux, with amplification counterbalanced by loss of insertions. Tnt1 insertion polymorphisms are too high to reveal species relationships in the Nicotiana genus, but can be used to evaluate species relationships in the Lycopersicon and Capsicum genera. This also demonstrates that the behavior of Tnt1 retrotransposons differs between host species, most probably in correlation to differences in expression conditions and in the evolutionary and environmental history of each host.


Asunto(s)
Genoma de Planta , Retroelementos , Solanaceae/genética , Secuencia de Bases , Regulación de la Expresión Génica de las Plantas , Datos de Secuencia Molecular , Mapeo Restrictivo , Secuencias Repetidas Terminales
12.
Braz J Biol ; 65(1): 159-68, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16025914

RESUMEN

Biodiversity corridors comprise a mosaic of land uses connecting fragments of natural forest across a landscape. Two such corridors have been established along the eastern coast of Brazil: the Serra do Mar and the Central da Mata Atlântica corridors, along which most of the coastal plains are restinga areas. In this study, we analyze the present status of the endemic and endangered terrestrial vertebrates of both corridors. We sampled 10 restingas in both corridors, recording species of amphibians, reptiles, birds, and mammals. Some restingas harbor a relatively large number of endemic species,and two main regions of endemism can be identified along the restingas of both corridors: the coastal restingas from northern Espirito Santo State to southern Bahia State (between Linhares, ES, and Tarancoso, BA), and the coastal region between the restingas of Maricá and Jurubatiba, Rio de Janeiro State. Six species of terrestrial vertebrates considered threatened with extinction are found in the restingas of Serra do Mar and Central da Mata Atlântica biodiversity corridors (Liolaemus lutzae, Formicivora littoralis, Mimus gilvus, Schistochlamys melanopis, and Trinomys eliasi). The region located between the restinga of Maricá and that of Jurubatiba is of special relevance for the conservation of vertebrate species of the restingas of the corridors because a considerable number of threatened species of terrestrial vertebrates are found there. We strongly recommend efforts to develop checklists of threatened faunas for the States of Espirito Santo and Bahia.


Asunto(s)
Biodiversidad , Árboles , Vertebrados/clasificación , Animales , Brasil , Densidad de Población
13.
Braz J Biol ; 75(2): 261-7, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-26132005

RESUMEN

In general, anurans tend to be nocturnal, though diurnal activity is characteristic of some groups. Studies show that frog activity may be inferred based on the number of individuals collected at different periods of the day, during large-scale field surveys. We investigated the best period of the day to conduct amphibian sampling in nine Atlantic Rainforest areas in southeastern Brazil, based on intensive field surveys. At each locality we employed similar sampling effort during diurnal, crepuscular and nocturnal searches (totaling 704.5 sampling hours). We pooled data from all localities for each period and estimated the proportion of frogs of each species active at each period based on the total number of individuals and on the number of species found during all surveys for that period. We recorded a total of 817 individual frogs from 69 species. Species richness was highest at night (median = 12 species), intermediate at dusk (median = 8), and lowest during the day (median = 4). The percentage of the total number of individual frogs found (pooled species) was highest during the night (ca. 53%) and lowest during the day (ca. 14%). Analyzing each species separately, the number of individuals recorded was consistently higher at dusk and night for most species. Our study evidences a trend for nocturnal activity for most Atlantic Rainforest frogs, with few species having primarily diurnal habits. Those results may favor future studies and conservation efforts for amphibian species.


Asunto(s)
Anuros/fisiología , Conducta Animal/fisiología , Biodiversidad , Ritmo Circadiano/fisiología , Animales , Anuros/clasificación , Brasil , Bosques , Densidad de Población
14.
Gene ; 208(2): 207-13, 1998 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-9524267

RESUMEN

The human gene XPB, defective in xeroderma pigmentosum patients complementation group B, encodes a DNA helicase involved in several DNA metabolic pathways, including DNA repair and transcription. The high conservation of this gene has allowed the cloning of homologs in various species, such as mouse, yeast and Drosophila. Not much information on the molecular basis of nucleotide excision repair in plants is available, but these organisms may have similar mechanisms to other eukaryotes. A homolog of XPB was isolated in Arabidopsis thaliana by using polymerase chain reaction (PCR) with degenerate oligonucleotides based on protein domains which are conserved among several species. Screening of an Arabidopsis cDNA library led to the identification and isolation of a cDNA clone with 2670 bp encoding a predicted protein of 767 amino acids, denoted araXPB. Genomic analysis indicated that this is a nuclear single copy gene in plant cells. Northern blot with the cDNA probe revealed a major transcript which migrated at approx. 2,800 b, in agreement with the size of the cDNA isolated. The araXPB protein shares approximately 50% identical and 70% conserved amino acids with the yeast and human homologs. The plant protein maintains all the functional domains found in the other proteins, including nuclear localization signal, DNA-binding domain and helicase motifs, suggesting that it might also act as part of the RNA transcription apparatus, as well as nucleotide excision repair in plant cells.


Asunto(s)
Arabidopsis/genética , Arabidopsis/metabolismo , ADN Helicasas/genética , Proteínas de Unión al ADN/genética , Secuencia de Aminoácidos , Animales , Clonación Molecular , Secuencia Conservada , ADN Helicasas/química , ADN Complementario , ADN de Plantas/genética , Proteínas de Unión al ADN/biosíntesis , Proteínas de Unión al ADN/química , Drosophila/genética , Genes de Plantas , Humanos , Ratones , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Saccharomyces cerevisiae/genética , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Xerodermia Pigmentosa/genética
15.
Mutat Res ; 174(4): 265-9, 1986 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-3526141

RESUMEN

Ascorbate (vitamin C) in the presence of copper yields H2O2, which seems to be responsible for its toxic effects in bacteria. However, we found that the Escherichia coli xthA mutant strain, which is hypersensitive to H2O2, has almost the same sensitivity as the wild-type strain to ascorbate and copper treatment. Our results suggest that the DNA damage induced in E. coli by H2O2 generated in oxidized ascorbate solutions is different from that induced by direct H2O2 treatment.


Asunto(s)
Ácido Ascórbico/farmacología , Cobre/farmacología , Escherichia coli/genética , Peróxido de Hidrógeno/farmacología , Proteínas Bacterianas/genética , Proteínas Bacterianas/fisiología , Reparación del ADN , Farmacorresistencia Microbiana , Escherichia coli/efectos de los fármacos , Escherichia coli/enzimología , Exodesoxirribonucleasas/genética , Exodesoxirribonucleasas/fisiología , Radicales Libres , Oxidación-Reducción
16.
Braz J Med Biol Res ; 37(4): 459-77, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15064809

RESUMEN

We report novel features of the genome sequence of Leptospira interrogans serovar Copenhageni, a highly invasive spirochete. Leptospira species colonize a significant proportion of rodent populations worldwide and produce life-threatening infections in mammals. Genomic sequence analysis reveals the presence of a competent transport system with 13 families of genes encoding for major transporters including a three-member component efflux system compatible with the long-term survival of this organism. The leptospiral genome contains a broad array of genes encoding regulatory system, signal transduction and methyl-accepting chemotaxis proteins, reflecting the organism's ability to respond to diverse environmental stimuli. The identification of a complete set of genes encoding the enzymes for the cobalamin biosynthetic pathway and the novel coding genes related to lipopolysaccharide biosynthesis should bring new light to the study of Leptospira physiology. Genes related to toxins, lipoproteins and several surface-exposed proteins may facilitate a better understanding of the Leptospira pathogenesis and may serve as potential candidates for vaccine.


Asunto(s)
Genoma Bacteriano , Leptospira interrogans/genética , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/fisiología , Leptospira interrogans/clasificación , Leptospira interrogans/fisiología , Datos de Secuencia Molecular , Transporte de Proteínas/genética , Transporte de Proteínas/fisiología , Análisis de Secuencia de ADN
17.
Braz J Biol ; 64(1): 135-9, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15195372

RESUMEN

We examined the stomach contents of 21 specimens of Mabuya agilis (Sauria; Scincidae) collected during February 2001 at the restinga habitat of Praia do Sul, in Ilha Grande, RJ, Brazil. Diet was composed of various types of small arthropods, with no plant material being eaten. Spiders were the most important items in the diet, followed by orthopterans. Apart from the absence of isopterans, the diet of Mabuya agilis from this insular area was similar to those of other conspecific mainland populations. This suggests that factors such as insularity and the absence of other small sympatric lizards may not have a significant effect on the feeding habits of the Praia do Sul population.


Asunto(s)
Conducta Alimentaria/fisiología , Contenido Digestivo , Lagartos/fisiología , Animales , Brasil , Ecosistema , Femenino , Masculino
18.
Braz J Biol ; 64(2): 353-6, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15462309

RESUMEN

Information on the ecology of lizard species from the Brazilian Atlantic Forest is scarce and almost nothing is known about the ecology of lizards of the genus Enyalius. In this study, we provide information about some aspects of the natural history of E. brasiliensis from an area of Atlantic Forest in Ilha Grande, RJ. Enyalius brasiliensis (N = 15) feeds mainly on arthropods. The most frequent food items were insect larvae, orthopterans, and ants; in terms of volume, larvae and termites were the most important food items; ants and termites were the most numerous prey categories. Two females were reproductive (one had 10 and the other, five vitellogenic follicles); the smallest measured 92.4 mm in SVL. Seven lizards were found on forest leaf litter. The other microhabitats used were vines, fallen logs, branches, and a crevice on a slope.


Asunto(s)
Lagartos/fisiología , Animales , Brasil , Ecosistema , Conducta Alimentaria/fisiología , Femenino , Contenido Digestivo , Masculino , Reproducción/fisiología , Árboles
19.
Braz J Biol ; 61(2): 287-94, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11514896

RESUMEN

We analyzed the thermal ecology and activity patterns of the lizard community from the Restinga of Jurubatiba, Rio de Janeiro, Brazil. The broadest activity was that of Tropidurus torquatus, a sit-and-wait forager, while the active foraging teiid Cnemidophorus littoralis had the shortest activity. The nocturnal gekkonid Hemidactylus mabouia was found active during the day only during early morning and late afternoon, when environmental temperatures are low. Body temperature was highest for Cnemidophorus littoralis and lowest for the two Mabuya species. The patterns found here are discussed and compared to those of congeneric species in other habitats in Brazil.


Asunto(s)
Conducta Animal/fisiología , Temperatura Corporal/fisiología , Lagartos/fisiología , Animales , Brasil , Femenino , Masculino , Temperatura
20.
Braz J Biol ; 63(3): 393-9, 2003 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-14758698

RESUMEN

We studied the parasitism by larvae of the chigger mite Eutrombicula alfreddugesi on the lizard community of Restinga de Jurubatiba, Rio de Janeiro State, Southeastern Brazil. We investigated the patterns of infestation (prevalence and intensity) of chigger mites in four sympatric lizards: Tropidurus torquatus, Mabuya agilis, M. macrorhyncha and Cnemidophorus littoralis. All lizards collected were checked for the presence of mites, which were counted under stereomicroscope. We tested the relationship between intensity of infestation and lizard body size for each species using regression analysis. The prevalences and mean intensities (+ one standard deviation) of infestation on each host species were, respectively: 100%; 86.4 + 94.6 in T. torquatus (n = 62); 100%; 20.9 + 9.3 in M. agilis (n = 7); 100%; 11.1 + 13.1 in M. macrorhyncha (n = 12); and 95.2%; 19.1 + 16.8 in C. littoralis (n = 21). Only for C. littoralis did body size significantly affect the intensity of infestation (r = 0.27, p = 0.02). For all lizard species, the body parts where chiggers occurred with the highest intensity were those of skin folds and joint regions.


Asunto(s)
Lagartos/parasitología , Infestaciones por Ácaros/veterinaria , Ácaros , Animales , Brasil , Interacciones Huésped-Parásitos , Ácaros/fisiología , Prevalencia
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