title: Protistan parasite QPX of hard-shell clam Mercenaria mercenaria is a member of Labyrinthulomycota.
abstract: Biomass of the protistan parasite QPX (quahaug parasite X) of hard-shell clam Mercenaria mercenaria was enriched from in vitro culture. The nuclear gene encoding the 18S RNA of the small-subunit ribosomal (ssu-rDNA) was recovered using the polymerase chain reaction (PCR) and sequenced. Phylogenetic analysis clearly showed that QPX is a member of phylum Labyrinthulomycota, within which it appears as a specific relative of Thraustochytrium pachydermum. These results confirm the provisional assignment of QPX to the Labyrinthulomycota made previously on the basis of morphological and ultrastructural characters found in some, but not all, geographic isolates.
authors: Institute for Marine Biosciences, National Research Council of Canada, Halifax, Nova Scotia. m.ragan@imb.uq.edu.au
authors: M A
authors: MA
authors: Ragan
authors: G S
authors: GS
authors: MacCallum
authors: C A
authors: CA
authors: Murphy
authors: J J
authors: JJ
authors: Cannone
authors: R R
authors: RR
authors: Gutell
authors: S E
authors: SE
authors: McGladdery
mesh_terms: D000818:Animals; D001483:Base Sequence; D049872:Bivalvia / Q000469:parasitology*; D016054:DNA, Protozoan / Q000737:chemistry / Q000302:isolation & purification; D004587:Electrophoresis, Agar Gel / Q000662:veterinary; D056890:Eukaryota / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D008969:Molecular Sequence Data; D009509:New Brunswick; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012337:RNA, Ribosomal, 18S / Q000737:chemistry; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D016054:DNA, Protozoan; D012337:RNA, Ribosomal, 18S