title: Differential Gene Expression in Liver, Gill, and Olfactory Rosettes of Coho Salmon (Oncorhynchus kisutch) After Acclimation to Salinity.
abstract: Most Pacific salmonids undergo smoltification and transition from freshwater to saltwater, making various adjustments in metabolism, catabolism, osmotic, and ion regulation. The molecular mechanisms underlying this transition are largely unknown. In the present study, we acclimated coho salmon (Oncorhynchus kisutch) to four different salinities and assessed gene expression through microarray analysis of gills, liver, and olfactory rosettes. Gills are involved in osmotic regulation, liver plays a role in energetics, and olfactory rosettes are involved in behavior. Between all salinity treatments, liver had the highest number of differentially expressed genes at 1616, gills had 1074, and olfactory rosettes had 924, using a 1.5-fold cutoff and a false discovery rate of 0.5. Higher responsiveness of liver to metabolic changes after salinity acclimation to provide energy for other osmoregulatory tissues such as the gills may explain the differences in number of differentially expressed genes. Differentially expressed genes were tissue- and salinity-dependent. There were no known genes differentially expressed that were common to all salinity treatments and all tissues. Gene ontology term analysis revealed biological processes, molecular functions, and cellular components that were significantly affected by salinity, a majority of which were tissue-dependent. For liver, oxygen binding and transport terms were highlighted. For gills, muscle, and cytoskeleton-related terms predominated and for olfactory rosettes, immune response-related genes were accentuated. Interaction networks were examined in combination with GO terms and determined similarities between tissues for potential osmosensors, signal transduction cascades, and transcription factors.
authors.affiliation: Department of Environmental Sciences, University of California, 2258 Geology Building, 900 University Ave, Riverside, CA, 92521, USA. lmary001@ucr.edu.
authors.forename: Lindley A
authors.initials: LA
authors.lastname: Maryoung
authors.affiliation: Department of Environmental Sciences, University of California, 2258 Geology Building, 900 University Ave, Riverside, CA, 92521, USA.
authors.forename: Ramon
authors.initials: R
authors.lastname: Lavado
authors.affiliation: Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Theo K
authors.initials: TK
authors.lastname: Bammler
authors.affiliation: Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Evan P
authors.initials: EP
authors.lastname: Gallagher
authors.affiliation: Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Patricia L
authors.initials: PL
authors.lastname: Stapleton
authors.affiliation: Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Richard P
authors.initials: RP
authors.lastname: Beyer
authors.affiliation: Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Federico M
authors.initials: FM
authors.lastname: Farin
authors.affiliation: Department of Medicine and Public Health and Center for Genomics Medicine, Medical University of South Carolina, 135 Cannon Street, Suite 303 MSC 835, Charleston, SC, 29425, USA.
authors.forename: Gary
authors.initials: G
authors.lastname: Hardiman
authors.affiliation: Department of Environmental Sciences, University of California, 2258 Geology Building, 900 University Ave, Riverside, CA, 92521, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Schlenk
mesh_terms: D000064:Acclimatization / Q000235:genetics / Q000502:physiology; D000818:Animals; D005786:Gene Expression Regulation / Q000235:genetics / Q000502:physiology*; D005880:Gills / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis / Q000662:veterinary; D017684:Oncorhynchus kisutch / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D064587:Osmoregulation / Q000235:genetics / Q000502:physiology; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D054712:Salinity; D012903:Smell / Q000235:genetics / Q000502:physiology
keywords: Gene expression; Microarray; Salinity; Salmonids