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Molecular Phylogeny of Labyrinthulids and Thraustochytrids Based On the Sequencing of 18s Ribosomal Rna Gene
Author(s) -
HONDA DAISKE,
YOKOCHI TOSHIHIRO,
NAKAHARA TORO,
RAGHUKUMAR SESHAGIRI,
NAKAGIRI AKIRA,
SCHAUMANN KARSTEN,
HIGASHIHARA TAKANORI
Publication year - 1999
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.1550-7408.1999.tb05141.x
Subject(s) - biology , 18s ribosomal rna , phylogenetic tree , sensu , phylogenetics , ribosomal rna , gene , molecular phylogenetics , ribosomal dna , 28s ribosomal rna , evolutionary biology , genus , genetics , zoology , rna , ribosome
Labyrinthulids and thraustochytrids are unicellular heterotrophs, formerly considered as fungi, but presently are recognized as members in the stramenopiles of the kingdom Protista sensu lato. We determined the 18S ribpsomal RNA gene sequences of 14 strains from different species of the six genera and analyzed the molecular phylogenetic relationships. the results conflict with the current classification based on morphology, at the genus and species levels. These organisms are separated, based on signature sequences and unique inserted sequences, into two major groups, which were named the labyrinthulid phylogenetic group and the thraustochytrid phylogenetic group. Although these groupings are in disagreement with many conventional taxonomic characters, they correlated better with the sugar composition of the cell wall. Thus, the currently used taxonomic criteria need serious reconsideration.