Heat shock protein expression in fish GEORGE K. IWAMA 1,  , PHILIP T. THOMAS { , ROBERT B. FORSYTH 1 and MATHILAKATH M. VIJAYAN 1, } 1 Department of Animal Science, and the Canadian Bacterial Diseases Network, University of British Columbia, Vancouver, BC, Canada V6T 1Z4 Contents Abstract page 35 General background 36 Molecular processes related to HSP expression 37 Heat shock protein studies in fish 40 Cell line studies Primary cell culture Whole animal studies Molecular characteristics of fish heat shock proteins The generalized stress response and HSP expression Methods of analysis 48 Applications 49 Acknowledgements 51 References 51 Abstract Heat shock proteins (HSP) are a family of proteins expressed in response to a wide range of biotic and abiotic stressors. They are thus also referred to as stress proteins. Their extraordinarily high degree of identity at the amino acid sequence level and the fact that this cellular stress response has been described in nearly all organisms studied, make this group of proteins unique. We provide a brief historical overview of HSP research, as a background to summarizing what is known about HSP expression in fish. The expression of HSPs in fish has been described in cell lines, primary cultures of various cells, and in the tissues of whole organisms. Collectively, the data show that the expression of HSPs are affected in a wide variety of fish cells and tissues, in response both to biological stressors such as infectious pathogens, as well as to abiotic stressors such as heat and cold shock, and environmental contaminants. HSP research in fish is in its early stages and many studies are describing the expression of proteins in response to various stressors. Several studies have contributed to our understanding of the molecular nature and the molecular biology of HSPs in fish. Recent studies have shown a relationship between HSP expression and the generalized stress response in 0960–3166 # 1998 Chapman & Hall  Author to whom correspondence should be addressed. E-mail: giwama@unixg.ubc.ca { Present address: Union Christian College, Dept. of Zoology, Alwaye–683 102, Kerala, India. } Present address: Bio-Stress Research, Vancouver, BC, Canada. Reviews in Fish Biology and Fisheries 8, 35–56 (1998)