Seasonal expressed sequence tags of rainbow smelt ( Osmerus mordax) revealed by subtractive hybridization and the identification of two genes up-regulated during winter

• Published in: Gene 2008-11, Vol.424 (1), p.56-62
• Main Authors: Richards, Robert C., Achenbach, John C., Short, Connie E., Kimball, Jennifer, Reith, Michael E., Driedzic, William R., Ewart, K. Vanya
• Format: Article
• Language: English
• Subjects: Acclimatization; Amino Acid Sequence; Animals; Cloning, Molecular; Cold Climate; Enzymes - genetics; Enzymes - metabolism; Expressed Sequence Tags; Gene Expression Regulation - physiology; Male; Molecular Chaperones - genetics; Molecular Sequence Data; Nucleic Acid Hybridization; Osmeriformes - genetics; Osmerus mordax; Polymerase Chain Reaction; Proteins - genetics; Proteins - metabolism; Reverse Transcriptase Polymerase Chain Reaction; Seasons; Sequence Homology, Amino Acid; Tacrolimus Binding Proteins - genetics
• ISSN: 0378-1119; 1879-0038
• DOI: 10.1016/j.gene.2008.08.002

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.