‘Geoarchaeote NAG1’ is a deeply rooting lineage of the archaeal order Thermoproteales rather than a new phylum
Guy L, Spang A, Saw J, Ettema T. 2014. ‘Geoarchaeote NAG1’ is a deeply rooting lineage of the archaeal order Thermoproteales rather than a new phylum. The ISME Journal. 8:1353–1357
Recent cultivation-independent studies have revealed a considerable diversity of uncultured and uncharacterized archaeal lineages. The genomic characterization of these lineages will be instrumental in order to shed light on their physiology and ecological significance and to provide an overall insight on the genomic diversity and evolution of the archaeal domain of life. In a recent issue of The ISME Journal, Kozubal et al. (2012) have used a metagenomic approach to obtain the composite genome of members of a ‘novel archaeal group 1’ (NAG1), isolated from a high-temperature acidic iron mat in Yellowstone National Park. Based on phylogenetic analysis of selected marker genes, Kozubal et al. (2012) concluded that NAG1 represented a novel phylum (‘Geoarchaeota’) in the Domain Archaea. Although we want to stress that we value the overall findings presented byKozubal et al. (2012) in terms of provided insights into metabolic and eco-physiological characteristics of the NAG1 lineage, we would like to contest the claim that NAG1 represents a novel archaeal phylum. As a main argument, we would like to point out that the phylogenetic approach used by Kozubal et al.(2012) is not suitable to place deeply rooting microbial lineages due to the nature of biological sequence data, which are, among others, affected by variations of evolutionary rates over time (heterotachy) and compositional bias.
- Type
- Journal Article
- Authors
- Guy, Lionel; Spang, Anja; Saw, Jimmy; Ettema, Thijs
- Units
- GRYN , YELL
- Keywords
- Archaea, depply rooting lineages, geoarchaeota, heterotachy, NAG 1, Taxonomy
- Subjects
- Ecological Framework: Water | Water Quality | Microorganisms