Abstract Background Collections of Clusters of Orthologous Genes (COGs) provide
indispensable tools for comparative genomic analysis, evolutionary reconstruction and …

Background An evolutionary classification of genes from sequenced genomes that
distinguishes between orthologs and paralogs is indispensable for genome annotation and …

Abstract The Clusters of Orthologous Genes (COG) database, also referred to as the
Clusters of Orthologous Groups of proteins, was created in 1997 and went through several …

In a recent article, Nelson-Sathi et al.(NS) report that the origins of major archaeal lineages
(MAL) correspond to massive group-specific gene acquisitions via HGT from bacteria …

Background The concept of a genomic core, defined as the set of genes ubiquitous in all
genomes of a monophyletic group, has become crucial in comparative and evolutionary …

Background Standard archival sequence databases have not been designed as tools for
genome annotation and are far from being optimal for this purpose. We used the database of …

The identification of orthologous relationships forms the basis for most comparative
genomics studies. Here, we present the second version of the eggNOG database, which …

Archaea comprise one of the three distinct domains of life (with bacteria and eukaryotes).
With 16 complete archaeal genomes sequenced to date, comparative genomics has …

Background Haloarchaea, a major group of archaea, are able to metabolize sugars and to
live in oxygenated salty environments. Their physiology and lifestyle strongly contrast with …

In vitro studies of the haloarchaeal genus Haloferax have demonstrated their ability to
frequently exchange DNA between species, whereas rates of homologous recombination …