title: Molecular phylogenetic analysis places Percolomonas cosmopolitus within Heterolobosea: evolutionary implications.
abstract: Percolomonas cosmopolitus is a common free-living flagellate of uncertain phylogenetic position that was placed within the Heterolobosea on the basis of ultrastructure studies. To test the relationship between Percolomonas and Heterolobosea, we analysed the primary structure of the actin and small-subunit ribosomal RNA (SSU rRNA) genes of P. cosmopolitus as well as the predicted secondary structure of the SSU rRNA. Percolomonas shares common secondary structure patterns of the SSU rRNA with heterolobosean taxa, which, together with the results of actin gene analysis, confirms that it is closely related to Heterolobosea. Phylogenetic reconstructions based on the sequences of the SSU rRNA gene suggest Percolomonas belongs to the family Vahlkampfiidae. The first Bayesian analysis of a large taxon sampling of heterolobosean SSU rRNA genes clarifies the phylogenetic relationships within this group.
authors.affiliation: Department of Evolutionary Biochemistry, A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia.
authors.forename: Sergey I
authors.initials: SI
authors.lastname: Nikolaev
authors.forename: Alexandre P
authors.initials: AP
authors.lastname: Mylnikov
authors.forename: Cedric
authors.initials: C
authors.lastname: Berney
authors.forename: Jose
authors.initials: J
authors.lastname: Fahrni
authors.forename: Jan
authors.initials: J
authors.lastname: Pawlowski
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Aleshin
authors.forename: Nikolay B
authors.initials: NB
authors.lastname: Petrov
mesh_terms: D000818:Animals; D016054:DNA, Protozoan / Q000032:analysis / Q000737:chemistry; D004275:DNA, Ribosomal / Q000032:analysis / Q000235:genetics; D056890:Eukaryota / Q000145:classification* / Q000235:genetics; D019143:Evolution, Molecular; D020459:Genes, rRNA / Q000235:genetics*; D010802:Phylogeny
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal