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Phylogeny of Trichomonads Inferred from Small‐Subunit rRNA Sequences
Author(s) -
GUNDERSON JOHN,
HINKLE GREGORY,
LEIPE DETLEF,
MORRISON HILARY G.,
STICKEL SHAWN K.,
ODELSON DAVID A.,
BREZNAK JOHN A.,
NERAD THOMAS A.,
MÜLLER MIKLOS,
SOGIN MITCHELL L.
Publication year - 1995
Publication title -
journal of eukaryotic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 1066-5234
DOI - 10.1111/j.1550-7408.1995.tb01604.x
Subject(s) - biology , monophyly , phylogenetic tree , phylogenetics , lineage (genetic) , protist , ribosomal rna , evolutionary biology , hindgut , maximum parsimony , 28s ribosomal rna , phylum , 18s ribosomal rna , zoology , genetics , botany , rna , clade , gene , ribosome , larva , midgut
. Small subunit (16S‐like) ribosomal RNA sequences were obtained from representatives of all four families constituting the order Trichomonadida. Comparative sequence analysis revealed that the Trichomonadida are a monophyletic lineage and a deep branch of the eukaryotic tree. Relative to other early divergent eukaryotic assemblages the branching pattern within the Trichomonadida is very shallow. This pattern suggests the Trichomonadida radiated recently, perhaps in conjunction with their animal hosts. From a morphological perspective the Devescovinidae and Calonymphidae are considered more derived than the Monocercomonadidae and Trichomonadidae. Molecular trees inferred by distance, parsimony and likelihood techniques consistently show the Devescovinidae and Calonymphidae are the earliest diverging lineages within the Trichomonadida, however bootstrap values do not strongly support a particular branching order. In an analysis of all known 16S‐like ribosomal RNA sequences, the Trichomonadida share most recent common ancestry with unidentified protists from the hindgut of the termite Reticulitermes flavipes. The position of two putative free‐living trichomonads in the tree is indicative of derivation from symbionts rather than direct descent from some free‐living ancestral trichomonad.