Submitted to: Biomed Central (BMC) Genomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/3/2004
Publication Date: 1/6/2005
Citation: Krasnov, A., Koskinen, H., Petri, P., Rexroad Iii, C.E., Afanasyev, S., Molsa, H. 2005. Gene expression in the brain and kidney of rainbow trout in response to handling stress. Biomed Central (BMC) Genomics 6:3. Interpretive Summary: Efforts aimed at the genetic improvement of agriculturally important species include the identification of genes controlling production traits. Stress can adversely affect production traits such as growth, disease susceptibility, and reproduction. We used microarray technology to observe changes in gene expression in the brains and kidneys of trout exposed to handling stress. Forty-eight genes showed tight coordination of expression in 35 microarray experiments being regulated with stress. Characterization of these genes will benefit scientists working to understand responses to stress at the molecular level.
Technical Abstract: Background. Microarray research is rapidly expanding towards new species including teleost fish. We constructed a rainbow trout cDNA microarray with special emphasis on environmental stress. This study focused on comparison of time-course of stress response in the brain and kidney and search for a diagnostic set of genes. Results. Fish were stressed with handling and samples were collected 1, 3 and 5 days after the first exposure. Stress affected different functional groups of genes in the studied tissues. Mitochondria, extracellular matrix and endopeptidases, especially collagenases were the major targets in kidney. Stress response in brain was characterized with dramatic temporal alterations. Metal ion binding proteins, glycolytic enzymes and motor proteins were induced transiently, whereas expression of genes involved in stress and immune response, cell proliferation and growth, signal transduction and apoptosis, protein biosynthesis and folding changed in a reciprocal way. We found a group of 48 genes that showed tight coordination of expression in 35 microarray experiments being regulated with stress. The microarray included clones from normalized and subtracted libraries and genes selected by the Gene Ontology categories. Performance of these groups was compared. The selected genes were markedly inferior to EST by the number of differentially expressed genes, however 63% of stress-responsive genes were from this group. Conclusions. 1. Stress responses in fish brain and kidney are different both by the target functions and time-course. 2. Finding of stress-regulated genes provides possibility for measurement of stress in various conditions and further search for the functionally related genes.