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Molecular phylogeny of phyllopharyngen ciliates and their novel Group I introns
Author(s) -
SNOEYENBOSWEST OONA L.O.,
COLE JEFFREY,
CAMPBELL ANNA,
COATS D. WAYNE,
KATZ LAURA A.
Publication year - 2005
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.1550-7408.2005.05202003_1_73.x
Subject(s) - biology , monophyly , intron , phylogenetic tree , ribosomal dna , phylogenetics , evolutionary biology , tetrahymena , ribosomal rna , genetics , gene , clade
We analyze small subunit ribosomal DNA (ssu‐rDNA) sequences to evaluate both the monophyly of the ciliate class Phyllopharyngea de Puytorac et al. (1974), and relationships among subclasses. Classifications based on morphology and ultrastructure divide the Phyllopharyngea into four subclasses: the Phyllopharyngia, Chonotrichia, Rhynchodia and Suctoria. Our analyses of ssu‐rDNA genealogies derived from sequence data collected from diverse members representing three of the four subclasses of Phyllopharyngea provide strong support for the monophyly of the Phyllopharyngea, and show that the Chonotrichia emerge from within the Phyllopharyngia. Based on this initial sampling, suctorian budding types are monophyletic, and exogenous budding appears to be basal to evaginative and endogenous budding. Further, we report the discovery of a group I intron at position 891 in the Suctoria Acineta sp. and Tokophrya lemnarum , and a second group I intron at position 1506 in T. lemnarum . These introns represent only the second examples of group I introns in a ciliate ribosomal gene, since the discovery of ribozymes in the LSU rRNA gene of Tetrahymena thermophila 20 years ago. Phylogenetic analyses of Group I introns suggest a complex evolutionary history involving either multiple loses or gains of introns within endogenously budding Suctoria.