title: Small subunit ribosomal DNA suggests that the xenophyophorean Syringammina corbicula is a foraminiferan.
abstract: Xenophyophorea are giant deep-sea rhizopodial protists of enigmatic origins. Although species were described as Foraminifera or sponges in the early literature, the xenophyophoreans are currently classified either as a class of Rhizopoda or an independent phylum. To establish the phylogenetic position of Xenophyophorea, we analysed the small subunit (SSU) rRNA gene sequence of Syringammina corbicula Richardson, a newly described xenophyophorean species from the Cape Verde Plateau. The SSUrDNA analyses showed that S. corbicula is closely related to Rhizammina algaeformis, a tubular deep-sea foraminiferan. Both species branch within a group of monothalamous (single-chambered) Foraminifera, which include also such agglutinated genera as Toxisarcon, Rhabdammina, and Saccammina, and the organic-walled genera Gloiogullmia and Cylindrogullmia. Our results are congruent with observations of similar cytoplasmic organisation in Rhizammina and Syringammina. Thus, the Xenophyophorea appear to be a highly specialised group of deep-sea Foraminifera.
authors.affiliation: Department of Zoology and Animal Biology, University of Geneva, CH-1211 Geneva 4, Switzerland. jan.pawlowski@zoo.unige.ch
authors.forename: Jan
authors.initials: J
authors.lastname: Pawlowski
authors.forename: Maria
authors.initials: M
authors.lastname: Holzmann
authors.forename: Jose
authors.initials: J
authors.lastname: Fahrni
authors.forename: Susan L
authors.initials: SL
authors.lastname: Richardson
mesh_terms: D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers; D016054:DNA, Protozoan / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D056890:Eukaryota / Q000145:classification*; D005784:Gene Amplification; D008969:Molecular Sequence Data; D010802:Phylogeny
chemical_list: D017931:DNA Primers; D016054:DNA, Protozoan; D004275:DNA, Ribosomal