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Registros recuperados: 10 | |
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Silva,Fernanda Britto da; Muschner,Valéria C.; Bonatto,Sandro L.. |
The phylum Placozoa, represented by its single species Trichoplax adhaerens, has always been considered one of the most basal animal clades due to its low morphological complexity. However, despite its importance, the phylogenetic position of the Placozoa remains uncertain, as does the relationships between the basal metazoans. We sequenced the nearly complete large subunit (LSU) of the T. adhaerens rRNA gene together with the small subunit (SSU) rRNA and used several methods to infer the phylogenetic position of Placozoa and the relationships between the basal animal phyla. The phylogenetic trees obtained from the LSU, SSU and SSU + LSU datasets support monophyly of all basal metazoan phyla, except the Porifera. However, the relationships between all... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Trichoplax adhaerens; Placozoa; Animal basal phylogeny; Metazoa relationship; RRNA genes. |
Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572007000100022 |
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Scherer,Nicole M.; Thompson,Claudia E.; Freitas,Loreta B.; Bonatto,Sandro L.; Salzano,Francisco M.. |
The genes encoding 13 classes of pathogenesis-related (PR) proteins were examined for positive selection using maximum-likelihood (ML) models of codon substitution. The study involved 194 sequences from 54 species belonging to 37 genera. Although the sizes of the sequences examined varied from 237 bp for PR12 to 1,110 bp for PR7, most classes (9 out of 13) contained sequences made up of more than 400 nucleotides. Signs of positive selection were obtained for sites in PR proteins 4, 6, 8, 9 and 15 using an ML-based Bayesian method and likelihood ratio tests. These results confirm the importance of positive selection in proteins related to defense mechanisms already observed in a wide array of organisms. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Pathogenesis-related proteins; PRs; Molecular variability; Positive selection; Maximum-likelihood methods. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000500001 |
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Mäder,Geraldo; Zamberlan,Priscilla M.; Fagundes,Nelson J.R.; Magnus,Tielli; Salzano,Francisco M.; Bonatto,Sandro L.; Freitas,Loreta B.. |
The discovery and characterization of informative intraspecific genetic markers is fundamental for evolutionary and conservation genetics studies. Here, we used nuclear ribosomal ITS sequences to access intraspecific genetic diversity in 23 species of the genus Passiflora L. Some degree of variation was detected in 21 of these. The Passiflora and Decaloba (DC.) Rchb. subgenera showed significant differences in the sizes of the two ITS regions and in GC content, which can be related to reproductive characteristics of species in these subgenera. Furthermore, clear geographical patterns in the spatial distribution of sequence types were identified in six species. The results indicate that ITS may be a useful tool for the evaluation of intraspecific genetic... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Genetic diversity; Intraspecific variability; ITS; Passiflora; Phylogeography. |
Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572010000100018 |
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Muschner,Valéria C.; Zamberlan,Priscilla M.; Bonatto,Sandro L.; Freitas,Loreta B.. |
As part of a long-term investigation on the evolution of Passiflora L., we investigated the divergence ages of the genus and diversification of its subgenera, relating them with biogeographical and/or historical events, and other characteristics of this taxon. The main aim of the present work was to evaluate the biogeographic distribution of this genus to better understand its evolutionary history. This is the first time that representatives from South American and Old World Passifloraceae genera have been studied as a group comprising a total of 106 widely distributed species, with representative samples of the four suggested subgenera. Seven DNA regions were studied, comprising 7,431 nucleotides from plastidial, mitochondrial and nuclear genomes.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biogeography; Molecular phylogenetics analysis; Passionflowers; Plant evolution; Taxonomic classification. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572012000600019 |
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Zaher,Hussam; Grazziotin,Felipe Gobbi; Cadle,John E.; Murphy,Robert W.; Moura-Leite,Julio Cesar de; Bonatto,Sandro L.. |
We present a molecular phylogenetic analysis of caenophidian (advanced) snakes using sequences from two mitochondrial genes (12S and 16S rRNA) and one nuclear (c-mos) gene (1681 total base pairs), and with 131 terminal taxa sampled from throughout all major caenophidian lineages but focussing on Neotropical xenodontines. Direct optimization parsimony analysis resulted in a well-resolved phylogenetic tree, which corroborates some clades identified in previous analyses and suggests new hypotheses for the composition and relationships of others. The major salient points of our analysis are: (1) placement of Acrochordus, Xenodermatids, and Pareatids as successive outgroups to all remaining caenophidians (including viperids, elapids, atractaspidids, and all... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Serpentes; Colubridae; Caenophidia; Phylogeny; Classification; Systematics; Xenodontinae; Dipsadinae; New genus; Elapoidea; Colubroidea; South America; West Indies. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0031-10492009001100001 |
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Registros recuperados: 10 | |
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