PHYLOGENY OF PHAGOTROPHIC EUGLENIDS (EUGLENOZOA): A MOLECULAR APPROACH BASED ON CULTURE MATERIAL AND ENVIRONMENTAL SAMPLES

Authors: Busse I.¹; Patterson D.J.²; Preisfeld A.

Source: Journal of Phycology, Volume 39, Number 4, August 2003 , pp. 828-836(9)

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Abstract:

Molecular studies based on small subunit (SSU) rDNA sequences addressing euglenid phylogeny hitherto suffered from the lack of available data about phagotrophic species. To extend the taxon sampling, SSU rRNA genes from species of seven genera of phagotrophic euglenids were investigated. Sequence analyses revealed an increasing genetic diversity among euglenid SSU rDNA sequences compared with other well-known eukaryotic groups, reflecting an equally broad diversity of morphological characters among euglenid phagotrophs. Phylogenetic inference using standard parsimony and likelihood approaches as well as Bayesian inference and spectral analyses revealed no clear support for euglenid monophyly. Among phagotrophs, monophyly of Petalomonas cantuscygni and Notosolenus ostium, both comprising simple ingestion apparatuses, is strongly supported. A moderately supported clade comprises phototrophic euglenids and primary osmotrophic euglenids together with phagotrophs, exhibiting a primarily flexible pellicle composed of numerous helically arranged strips and a complex ingestion apparatus with two supporting rods and four curved vanes. Comparison of molecular and morphological data is used to demonstrate the difficulties to formulate a hypothesis about how the ingestion apparatus evolved in this group.

Keywords: Anisonema; Bayesian inference; Dinema; Entosiphon; molecular phylogeny; Notosolenus; Peranema; Petalomonas; Ploeotia; SSU rDNA

Document Type: Research article

DOI: http://dx.doi.org/10.1046/j.1529-8817.2003.02178.x

Affiliations: 1: University of Bielefeld, Department of Biology, Postfach 100 131, 33501 Bielefeld, Germany 2: University of Sydney, School of Biological Sciences, NSW 2006, Australia

Publication date: 2003-08-01