The closest BLAST hit is often not the nearest neighbor.

摘要: It is well known that basing phylogenetic reconstructions on uncorrected genetic distances can lead to errors in their reconstruction. Nevertheless, it often common practice report simply the most similar BLAST (Altschul et al. 1997) hit genomic reports discuss many genes (Ruepp 2000; Freiberg 1997). This because hits provide a rapid, efficient, and concise analysis of at once. These are interpreted imply gene closely related or protein databases returned closest hit. Though these two may coincide, for genes, particularly with few homologs, they not be same. There number circumstances account such limitations accuracy (Eisen 2000). We stress here appearing based each others relative phylogenetically. The extent which this occurs depends availability close relatives present databases. As an example we have chosen genomes crenarcheaota species Aeropyrum pernix, organism fully sequenced, Escherichia coli, whose relative, Salmonella typhimurium, completely sequenced.