RESUMO
For a number of years the BioMart data warehousing system has proven to be a valuable resource for scientists seeking a fast and versatile means of accessing the growing volume of genomic data provided by the Ensembl project. The launch of the Ensembl Genomes project in 2009 complemented the Ensembl project by utilizing the same visualization, interactive and programming tools to provide users with a means for accessing genome data from a further five domains: protists, bacteria, metazoa, plants and fungi. The Ensembl and Ensembl Genomes BioMarts provide a point of access to the high-quality gene annotation, variation data, functional and regulatory annotation and evolutionary relationships from genomes spanning the taxonomic space. This article aims to give a comprehensive overview of the Ensembl and Ensembl Genomes BioMarts as well as some useful examples and a description of current data content and future objectives. Database URLs: http://www.ensembl.org/biomart/martview/; http://metazoa.ensembl.org/biomart/martview/; http://plants.ensembl.org/biomart/martview/; http://protists.ensembl.org/biomart/martview/; http://fungi.ensembl.org/biomart/martview/; http://bacteria.ensembl.org/biomart/martview/.
Assuntos
Classificação/métodos , Bases de Dados Genéticas , Armazenamento e Recuperação da Informação/métodos , Animais , Anopheles/genética , Biologia Computacional , Genoma/genética , Humanos , Fases de Leitura Aberta/genética , Polimorfismo de Nucleotídeo Único/genética , Ferramenta de BuscaRESUMO
The extent to which prokaryotic evolution has been influenced by horizontal gene transfer (HGT) and therefore might be more of a network than a tree is unclear. Here we use supertree methods to ask whether a definitive prokaryotic phylogenetic tree exists and whether it can be confidently inferred using orthologous genes. We analysed an 11-taxon dataset spanning the deepest divisions of prokaryotic relationships, a 10-taxon dataset spanning the relatively recent gamma-proteobacteria and a 61-taxon dataset spanning both, using species for which complete genomes are available. Congruence among gene trees spanning deep relationships is not better than random. By contrast, a strong, almost perfect phylogenetic signal exists in gamma-proteobacterial genes. Deep-level prokaryotic relationships are difficult to infer because of signal erosion, systematic bias, hidden paralogy and/or HGT. Our results do not preclude levels of HGT that would be inconsistent with the notion of a prokaryotic phylogeny. This approach will help decide the extent to which we can say that there is a prokaryotic phylogeny and where in the phylogeny a cohesive genomic signal exists.
Assuntos
Bactérias/genética , Classificação/métodos , Transferência Genética Horizontal/genética , Genoma Bacteriano , Filogenia , Funções Verossimilhança , Modelos GenéticosAssuntos
Genes Bacterianos , Mycobacterium tuberculosis/genética , Tuberculose/genética , Animais , Proteínas de Bactérias/genética , Evolução Biológica , Transferência Genética Horizontal , Humanos , Mycobacterium tuberculosis/imunologia , Mycobacterium tuberculosis/patogenicidade , Filogenia , Virulência/genéticaRESUMO
Mycobacterium tuberculosis is a high GC Gram-positive member of the actinobacteria. The mycobacterial cell wall is composed of a complex assortment of lipids and is the interface between the bacterium and its environment. The biosynthesis of fatty acids plays an essential role in the formation of cell wall components, in particular mycolic acids, which have been targeted by many of the drugs used to treat M. tuberculosis infection. M. tuberculosis has approximately 250 genes involved in fatty acid metabolism, a much higher proportion than in any other organism. In silico methods have been used to compare the genome of M. tuberculosis CDC1551 to a database of 58 complete bacterial genomes. The resulting alignments were scanned for genes specifically involved in fatty acid biosynthetic pathway I. Phylogenetic analysis of these alignments was used to investigate horizontal gene transfer, gene duplication, and adaptive evolution. It was found that of the eight gene families examined, five of the phylogenies reconstructed suggest that the actinobacteria have a closer relationship with the alpha-proteobacteria than expected. This is either due to either an ancient transfer of genes or deep paralogy and subsequent retention of the genes in unrelated lineages. Additionally, adaptive evolution and gene duplication have been an influence in the evolution of the pathway. This study provides a key insight into how M. tuberculosis has developed its unique fatty acid synthetic abilities.
