title: Species composition of the genus Saprolegnia in fin fish aquaculture environments, as determined by nucleotide sequence analysis of the nuclear rDNA ITS regions.
abstract: The ITS region of the rDNA gene was compared for Saprolegnia spp. in order to improve our understanding of nucleotide sequence variability within and between species of this genus, determine species composition in Canadian fin fish aquaculture facilities, and to assess the utility of ITS sequence variability in genetic marker development. From a collection of more than 400 field isolates, ITS region nucleotide sequences were studied and it was determined that there was sufficient consistent inter-specific variation to support the designation of species identity based on ITS sequence data. This non-subjective approach to species identification does not rely upon transient morphological features. Phylogenetic analyses comparing our ITS sequences and species designations with data from previous studies generally supported the clade scheme of Diéguez-Uribeondo et al. (2007) and found agreement with the molecular taxonomic cluster system of Sandoval-Sierra et al. (2014). Our Canadian ITS sequence collection will thus contribute to the public database and assist the clarification of Saprolegnia spp. taxonomy. The analysis of ITS region sequence variability facilitated genus- and species-level identification of unknown samples from aquaculture facilities and provided useful information on species composition. A unique ITS-RFLP for the identification of S. parasitica was also described.
authors.affiliation: Biology Department, Centre for Forest Biology, University of Victoria, P.O. Box 3020 STN CSC, Victoria, B.C. V8W 3N5, Canada. Electronic address: pdelabas@uvic.ca.
authors.forename: Paul Y
authors.initials: PY
authors.lastname: de la Bastide
authors.affiliation: Biology Department, Centre for Forest Biology, University of Victoria, P.O. Box 3020 STN CSC, Victoria, B.C. V8W 3N5, Canada. Electronic address: webby@uvic.ca.
authors.forename: Wai Lam
authors.initials: WL
authors.lastname: Leung
authors.affiliation: Biology Department, Centre for Forest Biology, University of Victoria, P.O. Box 3020 STN CSC, Victoria, B.C. V8W 3N5, Canada. Electronic address: whintz@uvic.ca.
authors.forename: William E
authors.initials: WE
authors.lastname: Hintz
mesh_terms: D000818:Animals; D017756:Aquaculture; D002170:Canada; D016000:Cluster Analysis; D048028:DNA, Algal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D005399:Fishes / Q000382:microbiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D044762:Saprolegnia / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA
chemical_list: D048028:DNA, Algal; D021903:DNA, Ribosomal Spacer
keywords: Fish pathogen; Genetic marker; Oomycete; Saprolegnia parasitica; Taxonomy