Variation in gene expression in response to stress in two populations of Fundulus heteroclitus.
We used differential display PCR to identify hepatic genes responsive to handling stress and genes that differ in expression between populations of a fish, Fundulus heteroclitus, from different thermal environments. Despite substantial inter-individual variation, we cloned 20 putatively stress-regulated bands from Northern fish, 10 of which had high similarity to genes of known function. We selected five of these genes for further analysis based on their known roles in the stress response. Three of these genes (glucokinase, serine-threonine kinase 10 and cRAF) were confirmed as stress-responsive using real-time PCR. These genes increased in expression in response to a 7-day chronic stress protocol in fish from the Southern population of F. heteroclitus, but did not change significantly in fish from the Northern population. These three genes also differed in expression between populations in control fish, suggesting a link between the response to chronic stress and inter-population differences in gene expression in unstressed laboratory-acclimated fish. Two genes that did not respond to stress (glycogen synthase kinase and warm acclimation-related protein (WAP)) also differed between populations. Expression of WAP was eight-fold higher in Southern than in Northern fish, consistent with a previously suggested role for this gene in thermal acclimation or adaptation in fish.
Picard
Daniel J
DJ
Department of Zoology, University of British Columbia, 6270 University Blvd., Vancouver, BC, Canada V6T 1Z4.
Schulte
Patricia M
PM
D000818:Animals; D004777:Environment; D029941:Fish Proteins / Q000235:genetics*; D023781:Fundulidae / Q000145:classification / Q000235:genetics*; D005786:Gene Expression Regulation; D005941:Glucokinase / Q000235:genetics; D038341:Glycogen Synthase Kinases / Q000235:genetics; D008099:Liver / Q000378:metabolism; D009656:North America; D019764:Phosphoenolpyruvate Carboxykinase (ATP) / Q000235:genetics; D016133:Polymerase Chain Reaction; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D019908:Proto-Oncogene Proteins c-raf / Q000235:genetics; D013312:Stress, Physiological / Q000235:genetics*
D029941:Fish Proteins; D005941:Glucokinase; D038341:Glycogen Synthase Kinases; D017346:Protein Serine-Threonine Kinases; D019908:Proto-Oncogene Proteins c-raf; D019764:Phosphoenolpyruvate Carboxykinase (ATP)