title: The split genes of Nanoarchaeum equitans have not originated in its lineage and have been merged in another Nanoarchaeota: a reply to Podar et al.
abstract: I reply to the suggestion of Podar et al. (2013) that the split genes of Nanoarchaeun equitans are a derived character, showing that their analysis is mistaken. In particular, I show that the split genes both proteins and tRNAs have not been split in N. equitans and have been on the contrary merged in the nanoarchaeon sequenced recently by Podar et al. (2013). This implies that the main argument of Podar et al. (2013) that there should be: "a unique propensity for splitting in the Nanoarchaeota that is most dramatically manifested in the Nanoarchaeum equitans lineage" is false. On the other hand, the analysis seems to favor the hypothesis that the split genes are an ancestral character. This would strengthen to greater extent a model for the origin of the tRNA molecule.
authors.affiliation: Laboratory for Molecular Evolution, Institute of Genetics and Biophysics 'Adriano Buzzati Traverso', CNR, Via P. Castellino, 111, 80131 Naples, Italy. Electronic address: massimo.digiulio@ibbr.cnr.it.
authors.forename: Massimo
authors.initials: M
authors.lastname: Di Giulio
mesh_terms: D019843:Archaeal Proteins / Q000235:genetics*; D020745:Genome, Archaeal; D046588:Nanoarchaeota / Q000502:physiology*; D016942:Sulfolobales / Q000502:physiology*; D013559:Symbiosis
chemical_list: D019843:Archaeal Proteins
keywords: Ancestral characters; Evolutionary stages; Parsimony; tRNA origin