We determined small subunit ribosomal DNA sequences from three parabasalid species, Trichomitus batrachorum strain R105, Tetratrichomonas gallinarum, and Pentatrichomonas hominis belonging to the Trichomonadinae subfamily. Unrooted molecular phylogenetic trees inferred by distance, parsimony, and likelihood methods reveal four discrete clades among the parabasalids. TheTrichomonadinae form a robust monophyletic group. Within this subfamily T. gallinarum is closely related to Trichomonas species as supported by morphological data, with P. hominis and Pseudotrypanosoma giganteum occupying basal positions. Our analysis does not place T. batrachorum within the Trichomonadinae. Trichomitus batrachorum (strains R105 and BUB) and Hypotrichomonas acosta form a well-separated cluster, suggesting the genus Trichomitus is polyphyletic. The emergence of T. batrachorum precedes the Trichomonadinae-Tritrichomonadinae dichotomy, emphasizing its pivotal evolutionary position among the Trichomonadidae. A third cluster unites the Devescovinidae and the Calonymphidae. The fourth clade contains the three hypermastigid sequences from the genus Trichonympha, which exhibit the earliest emergence among the parabasalids. The addition of these three new parabasalid species did not however resolve ambiguities regarding the relative branching order of the parabasalid clades. The phylogenetic positions of Tritrichomonas fœtus, Monocercomonas sp., Dientamoeba fragilis, and the unidentified Reticulitermes flavipes gut symbiont 1 remain unclear.
How to translate text using browser tools
1 January 2000
Molecular Phylogeny of Parabasalids Based on Small Subunit rRNA Sequences, with Emphasis on the Trichomonadinae Subfamily
Pilar Delgado-Viscogliosi,
Eric Viscogliosi,
Delphine Gerbod,
Jaroslav Kulda,
Mitchell L. Sogin,
Virginia P. Edgcomb
ACCESS THE FULL ARTICLE
It is not available for individual sale.
This article is only available to subscribers.
It is not available for individual sale.
It is not available for individual sale.
The Journal of Eukaryotic Microbiology
Vol. 47 • No. 1
January 2000
Vol. 47 • No. 1
January 2000
evolution
Parabasala
phylogeny
small subunit rRNA
taxonomy
trichomonad