Submitted to: Fish Physiology and Biochemistry Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 19, 2003
Publication Date: July 1, 2004
Citation: Silverstein, J. 2004. Using genetic variation to understand control of feed intake in fish. Fish Physiology and Biochemistry Journal.27:173-178. Interpretive Summary: Developing rainbow trout with superior growth and feed efficiency attributes is a central objective of our research, and both these traits are tied to feed intake. This paper describes research we have conducted along two parallel and complementary lines of investigation. One line of research was to characterize the physiological control of feed intake, and the other was to define the genetic variation for feed intake in a population of channel catfish. The ultimate goal is to understand the genetic basis of variation in feed intake and enable more accurate selection of animals with superior performance. This paper describes how the interaction between genetic studies and physiological studies led to identification in intake control genes in mice and the progress we have made with catfish.
Technical Abstract: The overall goal of our research is to develop fish with superior growth, and feed efficiency attributes. Feed intake is integral to these characters. Over the last several years we have been working with channel catfish, Ictalurus punctatus, in two directions tied to feed intake regulation. One direction has been to identify genes functioning as physiological regulators of feed intake, and the other has been to measure and characterize the genetic variation in feed intake within and among distinct catfish populations which reveal a wide range in feeding response. The goals are to uncover the genetic basis of physiological variation, to understand the genes and interactions that produce the phenotypic differences observed and to exploit these differences in a selective breeding program. To investigate the links between genetic variation and physiological variation, differences in voluntary feed consumption were documented in two strains of channel catfish. Treatment with orexigenic and anorexigenic compounds affected both strains similarly, through temperature treatment affected the strains differently with respect to feed efficiency. Variation in feed intake among families suggested that approximately 40% of the variation in feed intake is due to genetic sources. Future work aimed at identifying the specific genes responsible for this variation is discussed.