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United States Department of Agriculture

Agricultural Research Service

2007 Annual Report

1a.Objectives (from AD-416)
1. Establish two domesticated strains (even year and odd year populations) of rainbow trout selectively bred for improved growth and disease resistance. Genetic and phenotypic parameters for commercially important traits will be evaluated. The improved lines will be tested under field conditions in collaboration with trout farmers. 2. Provide physiological definition and characterization of growth, stress, and reproductive traits in rainbow trout. 3. Develop techniques for effective polyploidy induction to disrupt sexual development in rainbow trout.

1b.Approach (from AD-416)
A comprehensive multidisciplinary strategy utilizing quantitative genetic, physiological and molecular biological approaches is being used to produce genetically superior strains of rainbow trout for release to trout producers, and to develop the technologies for rapid and continued innovation and improvement. The initial step in this research will be to evaluate and characterize the broodstock established at NCCCWA. Offspring from crosses of six strains of rainbow trout will be evaluated for important aquaculture production traits e.g., growth, health, and reproductive development. These data will yield estimates of additive genetic variation among and within strains of rainbow trout and provide guidance for designing selection and breeding programs for genetic improvement. We will continue development and testing of rainbow trout lines that are transgenic for disease resistance genes. Physiological research will focus on defining critical pathways, and molecules in those pathways, for economically important traits. Furthermore, animals with extreme phenotypes, identified in the quantitative genetic anaylses, will be used in physiological studies to define the critical physiological differences. Specific breeding aids such as polyploidy and sex-reversal (to produce all female lines) will be applied to select families to provide benefits to rainbow trout aquaculture.

3.Progress Report
This report serves to document research conducted under a specific cooperative agreement between ARS and North Carolina State University (1930-31000-007-03S, Evaluation of Genotype by Environment Interactions in Rainbow Trout). In 2007 a student at NCSU began analysis of the data from the 20 genetic groups grown at both the NCSU extension facility in Fletcher, NC and in our Leetown, WV facility for performance comparison over multiple environments. The best performing groups in North Carolina were also the top performing groups in WV. Our analyses will provide estimates of the proportion of variation among environments due to genotype, environment and genotype x environment interaction. Monitoring was accomplished through meetings with the student and faculty member, reciprocal site visits and regular phone discussions with the student.

Additionally, this report documents research conducted under a specific cooperative agreement between ARS and University of Idaho (1930-31000-007-04S, Evaluation of Selected Rainbow Trout Lines Fed Grain Based Diets Under Farm Scale Conditions). Fish from 8 genetic groups were evaluated at the University of Idaho, Hagerman facility. Each genetic group was divided into 2 groups and fed either a control diet high in fishmeal content or a diet high in protein from soybean meal. The affect of high soy diet on spawning success was examined. Some differences in mean fecundity, fertilization and hatch rates were apparent. Monitoring was accomplished through telephone discussions.

Another specific cooperative agreement between ARS and Dr. Thomas Chen at University of Connecticut is ongoing (1930-31000-007-05S) Development of Superior Rainbow Trout Broodstocks for Aquaculture by Transgenesis). In FY 2007 this project has progressed to the second generation in several additional lines with targeted transgenes that appear to have enhanced disease resistance. Other groups of transgenic rainbow trout have been bred to the F2 generation. Monitoring was accomplished via telephone discussions and periodic written reports.

Title: Breeding for resistance to bacterial cold-water disease Problem: Bacterial coldwater disease (CWD) is the major bacterial pathogen affecting trout aquaculture. As part of a multifaceted approach to disease control, the genetic parameters for resistance to CWD, and correlations with fish growth are being investigated. Accomplishment: In 2007, we determined there is not an antagonistic genetic relationship between resistance to coldwater disease and growth, both can be improved simultaneously. Additionally, we selectively bred rainbow trout families for improved resistance to challenge with the pathogen causing coldwater disease and placed select and control lines of fish on commercial fish farms. In seperate controlled challenges our selectively bred fish showed improved resistance. Impact: This work is expected to offer growers a fish more resistant to the most important bacterial disease affecting trout culture.

NP 106-Aquaculture; Genetic improvement; Selective breeding for commercially important traits.

Title: Genes regulating egg development Problem: Improving egg quality, reflected by better fertilization and hatching rates is important for the trout industry. We are examining the localization and time course of gene expression of a suite of genes thought to regulate oocyte development in the stages just prior to spawning. Accomplishment: Our work has shown differences in the location of expression of several key genes, Activin A and BAMBI in the follicle cells whereas BMP4, BMP7 and GDF9 are predominantly expressed in the oocyte. Additionally, this work has revealed the time course of events leading up to spawning. Impact: Our data suggest that these peptides may be critical to the process of egg development and therefore may be important for egg quality.

NP 106- Aquaculture; Reproduction and early development; Elucidate processes involved in gamete production.

6.Technology Transfer

Number of new CRADAs and MTAs2
Number of active CRADAs and MTAs2
Number of non-peer reviewed presentations and proceedings7

Review Publications
Weber, G.M., Moore, A.B., Sullivan, C.V. 2007. In Vitro Actions of Insulin-like Growth Factor-I on Ovarian Follicle Maturation in White Perch (Morone americana). General and Comparative Endocrinology 151, 180-187.

Rodgers, B.D., Roalson, E.H., Weber, G.M., Roberts, S.B., Goetz, F.W. 2006. A proposed nomenclature consensus for the myostatin gene family. American Journal of Physiology - Endocrinology and Metabolism 292:371-372.

Shepherd, B.S., Johnson, J.K., Silverstein, J., Parhar, I., Vijayan, M.M., McGuire, A., Weber, G.M. 2006. Endocrine and orexigenic effects of growth hormone secretogogues in rainbow trout (Oncorhynchus mykiss). Comparative Biochemistry and Physiology. Part A 146(2007):390-399.

Weber, G.M., Silverstein, J. 2006. Evaluation of a stress response for use in a selective breeding program for improved growth and disease resistance in rainbow rout (oncorhynchus mykiss). North American Journal of Aquaculture. 69:69-79.

Bosworth, B.G., Wolters, W.R., Silverstein, J., Li, M.H., Robinson, E.H. 2006. Family, strain, gender, and dietary protein effects on production and processing traits of norris and NWAC103 strains of channel catfish, Ictalurus punctatus. North American Journal of Aquaculture 69:106-115.

Last Modified: 12/21/2014
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