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United States Department of Agriculture

Agricultural Research Service

Research Project: INTEGRATION OF NUTRITIONAL, GENETIC AND PHYSIOLOGICAL APPROACHES TO IMPROVE PRODUCTION EFFICIENCY OF RAINBOW TROUT

Location: Small Grains and Potato Germplasm Research

Title: Evaluating the Expression of Immunologic Factors in Regards to Dietary and Pathogen Immunostimulation

Authors
item Overturf, Kenneth
item Johansen, Katherine - FORMER USDA ARS EMPLOYEE
item Sealy, Wendy - UNIV OF ID, HAGERMAN, ID

Submitted to: International Aquatic Animal Health Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: April 15, 2006
Publication Date: September 13, 2006
Repository URL: http://riley.nal.usda.gov/nal_web/digi/submission.html
Citation: Overturf, K., Sealey, W.M., and LaPatra, S. (2006) Evaluating the expression of immunologic factors in regards to dietary and pathogen immunostimulation. Book of Abstracts 5th International Symposium on Aquatic Animal Health #128 pg 207.

Interpretive Summary: Studies involving fish growth and disease resistance rely heavily on monitoring physical parameters such as overall weight gain, and fillet weight, or mortality after exposure and immunological activity. These measurements do provide valuable information, in a general manner, in regards to variation between control and treatment groups. The recent substantial increase in genome sequence information for trout and other species now allows for the generation of assays for the analysis of expression for genes of interest. These assays can be used to study the effects of immunological stimulus on genes of known function or to develop assays that correlate expression changes with known changes in animal physiology. We have developed a number of assays in our lab for examining the expression of genes involved with muscle development, immunology, and metabolism. In some experiments there is a high correlation between level of gene expression and treatment. We are now using these assays to study how immune stimulation affects muscle growth in aquaculture species. Specifically we are examining what immune genes are stimulated by specific pathogens and how these, and immunostimulants added into diets affect muscle growth. To test this possibility, a rainbow trout model for chronic immune stimulation was developed and characterized whereby chronic upregulation of TNF by lipopolysaccharide injection was found to decrease muscle ratios in rainbow trout. We are now looking to better characterize the pathways involved with decreased muscle growth and the role of disease reducing muscle specific growth.

Technical Abstract: Studies involving fish growth and disease resistance rely heavily on monitoring physical parameters such as overall weight gain, and fillet weight, or mortality after exposure and immunological activity. These measurements do provide valuable information, in a general manner, in regards to variation between control and treatment groups. The recent substantial increase in genome sequence information for trout and other species now allows for the generation of assays for the analysis of expression for genes of interest. These assays can be used to study the effects of immunological stimulus on genes of known function or to develop assays that correlate expression changes with known changes in animal physiology. We have developed a number of real-time quantitative PCR assays in our lab for examining the expression of genes involved with muscle development, immunology, and metabolism. In some experiments there is a high correlation between level of gene expression and treatment. We are now using these assays to study how immune stimulation affects muscle growth in aquaculture species. Specifically we are examining what immune genes are stimulated by specific pathogens and how these, and immunostimulants added into diets affect muscle growth. To test this possibility, a rainbow trout model for chronic immune stimulation was developed and characterized whereby chronic upregulation of TNF by lipopolysaccharide injection was found to decrease muscle ratios in rainbow trout. We are now looking to better characterize the pathways involved with decreased muscle growth and the role of disease reducing muscle specific growth.

Last Modified: 4/17/2014
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