title: Seasonal expressed sequence tags of rainbow smelt (Osmerus mordax) revealed by subtractive hybridization and the identification of two genes up-regulated during winter.
abstract: The rainbow smelt (Osmerus mordax) is freeze-resistant and maintains swimming and feeding activity during winter. In order to identify genes differentially expressed in smelt liver response to winter water temperatures, a large-scale analysis of gene expression using suppression subtractive hybridization was carried out using samples obtained in fall and winter. Forward and reverse subtractions were performed, subtraction-enriched products were cloned, and clones were sequenced from both of the resulting libraries. When 27 of these genes were screened by semi-quantitative RT-PCR to identify candidates for differential expression based generally on 2-fold changes in expression, one encoding FK506-binding protein 5 was classified as up-regulated in response to seasonal change, another encoding the mitochondrial solute carrier 25 member 25 (ATP-Mg/Pi carrier) was similarly classified with seasonal change and low temperature shift, and the one encoding the 78 kDa glucose-regulated protein was provisionally classified as down-regulated with low temperature shift. Analysis of fall (warm) and winter (cold) seasonal samples by quantitative PCR (qPCR) revealed significant up-regulation of genes encoding FK506-binding protein 51 and the mitochondrial solute carrier, whereas the gene encoding the glucose-regulated protein showed no significant change in expression. The mitochondrial solute carrier and FK506-binding protein results may relate to changes in cortisol action, as both are regulated by cortisol in other species.
authors.affiliation: Institute for Marine Biosciences, National Research Council, Halifax, NS, Canada B3H 3Z1.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Richards
authors.forename: John C
authors.initials: JC
authors.lastname: Achenbach
authors.forename: Connie E
authors.initials: CE
authors.lastname: Short
authors.forename: Jennifer
authors.initials: J
authors.lastname: Kimball
authors.forename: Michael E
authors.initials: ME
authors.lastname: Reith
authors.forename: William R
authors.initials: WR
authors.lastname: Driedzic
authors.forename: K Vanya
authors.initials: KV
authors.lastname: Ewart