100 research outputs found
Taxonomia dos camundongos-do-mato, gênero Oligoryzomys Bangs, 1900 (Rodentia, Sigmodontinae) do Cerrado brasileiro, com a descrição de duas novas espécies
We present a taxonomic overview of the species of Oligoryzomys from the Brazilian Cerrado. We recognize seven species, including two described herein, making Oligoryzomys one of the most diverse mammalian genera of the Cerrado morphoclimatic domain. Oligoryzomys chacoensis occurs in the Cerrado and Chaco morphoclimatic domains. Oligoryzomys flavescens is distributed mainly in the Atlantic Forest of Brazil and the Pampas region of Argentina and Uruguay, but is also found in gallery forest in the Cerrado of Brazil near the border of the Atlantic Forest. Oligoryzomys stramineus and O. fornesi occur in the Cerrado and Caatinga morphoclimatic domains. Oligoryzomys nigripes is found in the Atlantic Forest and in the Southern portion of the Cerrado. The two new species are endemic to the Cerrado, and one of them is found only in “campo rupestre” vegetation. Oligoryzomys eliurus and O. delticola are placed tentatively as junior synonyms of O. nigripes. Oligoryzomys fornesi is recognized as a distinct species from O. microtis.Apresentamos uma revisão taxonômica das espécies do gênero Oligoryzomys do Cerrado brasileiro. Reconhecemos sete espécies, incluindo duas aqui descritas, tornando Oligoryzomys um dos mais diversos gêneros de mamíferos do domínio morfoclimático do Cerrado. Oligoryzomys chacoensis ocorre nos domínios morfoclimáticos do Cerrado e do Chaco. Oligoryzomys flavescens se distribui principalmente na Mata Atlântica do Brasil e na região dos pampas da Argentina e Uruguai, mas é também encontrado em matas de galeria no Cerrado do Brasil próximo do limite com a Mata Atlântica. Oligoryzomys stramineus e O. fornesi ocorrem nos domínios morfoclimáticos do Cerrado e da Caatinga. Oligoryzomys nigripes é encontrado na Mata Atlântica e na porção sul do Cerrado. As duas novas espécies são endêmicas do Cerrado, e uma delas é encontrada apenas na vegetação de “campo rupestre”. Oligoryzomys eliurus e O. delticola são tentativamente consideradas sinônimos juniores de O. nigripes. Oligoryzomys fornesi é reconhecida como uma espécie distinta de O. microtis
O grupo de espécies Oryzomys subflavus, com descrição de duas espécies novas (Rodentia, Muridae, Sigmodontinae).
The sigmodontine rodent Oryzomys subflavus (Wagner, 1842) and two new species here described form the so-called Oryzomys subflavus species group of the genus Oryzomys. This group includes species of medium to large size, with tail longer than head and body, dorsal color changing gradually to the ventral parts, long foot of terrestrial/scansorial type, skull with supraorbital crests well developed and convergent, long and narrow incisive foramina, zygomatic plate projected forward, and posterolateral pits of palate included in a large fossa. The two new species, Oryzomys scotti sp.nov. and Oryzomys maracajuensis sp.nov., differ in karyotype, in pattern of the lower molars, in pelage of the dorsum and head, in presence or absence of the sphenoidal strut and of sphenopalatine vacuities. Their main habitats are several vegetal formations of the Cerrado and disturbed Atlantic Forest. The geographical distribution of these three species includes mainly the Cerrado and bordering areas of Atlantic Forest and Caatinga Biomes.O roedor sigmodontíneo Oryzomys subflavus (Wagner, 1842) e duas novas espécies aqui descritas constituem o chamado grupo O. subflavus dentro do gênero Oryzomys. Esse grupo é formado por espécies de tamanho médio a grande, com cauda maior que a cabeça e o corpo, cor do dorso mudando gradualmente para a cor do ventre, pé comprido de tipo terrestre/escansorial, crânio com cristas supraorbitárias desenvolvidas e convergentes, forame incisivo longo e estreito, placa zigomática projetada para frente e fossetas posterolaterais do palato incluídas numa fossa maior. As duas novas espécies, Oryzomys scotti sp.nov. e Oryzomys maracajuensis sp.nov., diferem no cariótipo, estrutura dos molares inferiores, pelagem do dorso e da cabeça, e presença ou ausência da escora alisfenoidal e de fenestras esfenopalatinas. Seus principais habitats são várias formações vegetais do Cerrado e a Floresta Atlântica degradada. A distribuição geográfica dessas três espécies inclui principalmente o bioma do Cerrado e áreas limítrofes dos biomas da Floresta Atlântica e da Caatinga
Identification, classification and evolution of Owl Monkeys (Aotus, Illiger 1811)
<p>Abstract</p> <p>Background</p> <p>Owl monkeys, belonging to the genus <it>Aotus</it>, have been extensively used as animal models in biomedical research but few reports have focused on the taxonomy and phylogeography of this genus. Moreover, the morphological similarity of several <it>Aotus </it>species has led to frequent misidentifications, mainly at the boundaries of their distribution. In this study, sequence data from five mitochondrial regions and the nuclear, Y-linked, <it>SRY </it>gene were used for species identification and phylogenetic reconstructions using well characterized specimens of <it>Aotus nancymaae</it>, <it>A. vociferans</it>, <it>A. lemurinus</it>, <it>A. griseimembra</it>, <it>A. trivirgatus</it>, <it>A. nigriceps</it>, <it>A. azarae boliviensis </it>and <it>A. infulatus</it>.</p> <p>Results</p> <p>The complete <it>MT-CO1</it>, <it>MT-TS1</it>, <it>MT-TD, MT-CO2</it>, <it>MT-CYB </it>regions were sequenced in 18 <it>Aotus </it>specimens. ML and Bayesian topologies of concatenated data and separate regions allowed for the proposition of a tentative <it>Aotus </it>phylogeny, indicating that <it>Aotus </it>diverged some 4.62 Million years before present (MYBP). Similar analyses with included GenBank specimens were useful for assessing species identification of deposited data.</p> <p>Conclusions</p> <p>Alternative phylogenetic reconstructions, when compared with karyotypic and biogeographic data, led to the proposition of evolutionary scenarios questioning the conventional diversification of this genus in monophyletic groups with grey and red necks. Moreover, genetic distance estimates and haplotypic differences were useful for species validations.</p
Análise cariológica e molecular de Proechimys Allen, 1899 (Rodentia, Echimyidae) da região Amazônica
Karyologic and molecular analyses were carried out in Proechimys quadruplicatus and two other Proechimys species from the northern bank of the Rio Negro, Brazil. Analyses of cytb DNA sequence data and karyologic attributes partially sustained the goeldii species group. Molecular analyses grouped the two Proechimys sp. A haplotypes here sequenced with other specimens from the Amazonian region of Brazil and Venezuela, suggesting that they belonged to a single taxon. The three specimens of Proechimys sp. B also formed a monophyletic group. Proechimys sp. A,Proechimys sp. B, and P. guyannensis were grouped by karyologic and/or molecular data indicating that they are very similar one another and belong to the same species group, the guyannensis group. Phylogeographic analyses showed a high geographic structuration in the Proechimys sp. A population and the presence of a median vector between haplotypes of different rivers suggested that the large Amazonian rivers are barrier to these population.Análises cariológicas e moleculares foram realizadas em Proechimys quadruplicatus e duas outras espécies de Proechimys da margem norte do rio Negro, Brasil. Análises da seqüência de ADN do citocromo b e dos atributos cariológicos sustentam parcialmente o grupo de espécies goeldii. As análises moleculares agruparam os dois haplótipos de Proechimys sp. A aqui seqüenciados com outros espécimes da região Amazônica do Brasil e Venezuela sugerindo que eles pertençam ao mesmo táxon. Os três espécimes de Proechimys sp. B formam um grupo monofilético. Proechimys sp. A, Proechimys sp. B e P. guyannensis se agrupam pelos dados moleculares e/ou cariológicos indicando que eles são bastantes similares e pertencem ao mesmo grupo de espécies, o grupoguyannenis. A análise filogeográfica mostrou um padrão de estruturação geográfica forte nas populações de Proechimys sp. A, e a presença de vetores médios entre os haplótipos de diferentes rios, na análise de “median - joining”, sugere que estes rios sejam barreiras para estas populações
A new species of Cerradomys (Mammalia: Rodentia: Cricetidae) from Central Brazil, with remarks on the taxonomy of the genus
Does the widely distributed rodent Calomys tener (Cricetidae: Sigmodontinae) constitute a single evolutionary unit?
The nominal species Calomys tener (Winge, 1887) ranges broadly in open lands of the Caatinga, Cerrado, Pantanal and Mata Atlântica of Brazil, and was recently reported from the Pampas of southern Brazil, and in the Selva Paranaense of eastern Paraguay and northeastern Argentina. This rodent can be infected with the pathogenic Araraquara hantavirus in Brazil. Given that most epidemiological studies have not taken into account updated taxonomic findings of their rodent hosts, in this study, we obtained sequence data of the Cyt-b and COI genes of specimens of C. tener from 22 different geographical localities from throughout the currently known distribution of the species (including individuals from Argentina, Paraguay, Bolivia, and Brazil) to test if it constitutes a single genetic unit or if it presents genetic discontinuities that may represent different evolutionary lineages. Phylogenetic analyses including several species of Calomys recovered several clades with strong support. Regarding C. tener, it is recovered as sister to the node that cluster C. laucha (Fischer, 1814) sensu lato, C. expulsus (Lund, 1841) and species in the C. callosus (Rengger, 1830) species complex. At the intraspecific level there are no genetic gaps among haplotypes of C. tener that could suggest more than one species. The recent captures in the Pampas of southern Brazil and in the Selva Paranaense suggest that the species may be colonizing new geographic areas.Fil: González Ittig, Raúl Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Kandel, Narayan P.. Texas Tech University. Department Of Biological Sciences; Estados UnidosFil: Bonvicino, Cibele R.. Instituto Nacional de Cáncer. División de Genetica; BrasilFil: Salazar-Bravo, Jorge. Texas Tech University. Department Of Biological Sciences; Estados Unido
New record of the rare Atlantic Forest rodent Phyllomys lundi (Mammalia: Rodentia)
ABSTRACT The arboreal echimyid rodent of the genus Phyllomys Lund, 1839 is found in the eastern Brazilian Atlantic forest, from the state of Ceará to the state of Rio Grande do Sul, reaching the São Francisco and Paraná river basins in the west. There are 13 species in the genus. Phyllomys lundi Leite, 2003, which until now was known from only two localities, is one of the four endemic Atlantic Forest species of Phyllomys with very restricted distribution. We provide additional data on the morphology, distribution and phylogeography (based on cytochrome b sequences) of the rare P. lundi . Our new record broadens the northern limit of the distribution P. lundi by approximately 250 km with respect to previous records
Human Papillomavirus in Brazilian women with and without cervical lesions
<p>Abstract</p> <p>Background</p> <p>Human Papillomavirus (HPV) high-risk (HR) types are the causal factor for cervical cancer and premalignant dysplasia. Data on frequency of HPV types provide a basis to design and evaluate HPV prevention programs. Taking into account the heterogeneity of HPV types across and within populations this study aims to access the HPV frequency in Brazilian women.</p> <p>Results</p> <p>We identified 24 different types of HPV, including a <it>Betapapillomavirus </it>and a likely new type, previously reported, from 132 women positive for the virus analysed by Hybrid Capture II assay. These women were infected by a single or multiple HPV types and 142 HPV strains were identified. HR types were found in 75% of women and HPV types 16, 18, 45, 58, and 66 had the highest frequency. Significant differences in frequency of HR HPV types were found for presence of cervical lesions, and for different HPV species and women age.</p> <p>Conclusions</p> <p>Compared with previous studies in Brazil, our data indicated differences in frequency and HPV type diversity, a significant association of other HR-types but HPV16 and 18 and cervical lesions, and a trend for distinct distribution of HPV types by age.</p
- …