A Molecular and Ultrastructural Description of Spathidiopsis buddenbrocki and the Phylogenetic Position of the Family Placidae (Ciliophora)

• Published in: The Journal of eukaryotic microbiology Vol. 59; no. 1; pp. 67 - 79
• Main Authors: Lipscomb, Diana L., Bowditch, Brunella M., Riordan, Gavin P.
• Format: Journal Article
• Language: English
• Published: Hoboken, NJ Blackwell Publishing Ltd 01-01-2012; Wiley
• Subjects: Biological and medical sciences; Ciliophora; Ciliophora - classification; Ciliophora - genetics; Ciliophora - ultrastructure; Cluster Analysis; Coleps; Cryptocaryon; DNA, Protozoan - chemistry; DNA, Protozoan - genetics; DNA, Ribosomal - chemistry; DNA, Ribosomal - genetics; Fundamental and applied biological sciences. Psychology; Genes, rRNA; Molecular Sequence Data; Organelles - ultrastructure; Phylogeny; Placus; Placus striatus; Prorodon; Prorodontida; Protista; Protozoa; RNA, Protozoan - genetics; RNA, Ribosomal, 18S - genetics; Sequence Analysis, DNA; small subunit rRNA; Protiste; Protozoa; Position; Ribosomal RNA; Taxonomy; Ciliophora; Prorodontida; Phylogeny; Subunit; Protista; small subunit rRNA; Placus
• ISSN: 1066-5234; 1550-7408
• DOI: 10.1111/j.1550-7408.2011.00595.x

ABSTRACT
Spathidiopsis and Placus are the only two genera within the family Placidae. The family has been placed in the class Prostomatea and order Prorodontida because its members have somatic monokinetids with a radial transverse ribbon, a straight non‐overlapping postciliary ribbon, and anteriorly directed non‐overlapping kinetodesmal fibril, an apical cytostome lacking specialized oral cilia, a brosse, and toxicysts. To confirm the stability of this placement, ultrastructural morphology and small subunit rRNA gene sequences of Spathidiopsis socialis, Spathidiopsis buddenbrocki, and Placus striatus were determined. These data were combined with information from other ciliates, and phylogenetic trees were generated using maximum‐likelihood and maximum‐parsimony methods. The analyses confirmed the family Placidae to be a monophyletic group in the Prostomatea with the Placidae a sister group to a Cryptocaryon + Coleps + Prorodon clade.