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Trout DNA May
Help Improve Fish
June 17, 2003
One hundred forty-five families of
rainbow trout at an Agricultural Research
Service lab in Leetown, W.Va., are providing genetic material that may help
ARS scientists breed fish that grow faster and resist diseases under varying
The ARS National Center for Cool and Cold Water Aquaculture (NCCCWA), which opened in 2001, oversees
this research. It includes studies on fish genetics and breeding, aquatic
animal health, nutrition, production system development and environmental
compatibility, according to lab director William Hershberger. Initial research
has focused on rainbow trout and other salmonids. Future research may include
striped bass, walleye and yellow perch.
The first generation of breeder fish, formed by cross-breeding two
commercially used strains, is complete. Breeder fish siblings were shipped to
other locations to evaluate their performance under different conditions. Some
have been sent to the University of
Fish Culture Experiment Station as part of the cooperative program to test
fish diets. Other fish from the same family are being raised at
West Virginia University, to
evaluate their performance in small production unit conditions.
Molecular biologist Caird E. Rexroad III is working on a genetic map of the
rainbow trout, Oncorhynchus mykiss, to assist in developing improved
strains. Rexroad and his colleagues have extracted genetic material, called
DNA, from each of the 145 families of trout and are adding to the genetic map
500 microsatellite markers they have produced. When finished, this trout map
will be used to identify genome areas that affect production trait differences
and allow the development of a fish useful to producers and consumers.
Researchers are working with the University of
Center in Storrs, Conn., to find genes that enhance growth rate, increase
disease resistance and improve stress response.
NCCCWA includes a 20,000-square-foot aquarium building with the latest in
water-treatment and recirculation technology, developed mostly from research at
the Conservation Fund's
Freshwater Institute in
Shepherdstown, W.Va., another NCCCWA cooperator.
More information on this research is in the
June issue of
Agricultural Research magazine.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.