Molecular biologists at the National Center for Cool and Cold Water Aquaculture (NCCCWA) are comparing the rainbow trout genes to similar genes in mammals that are known to be responsible for growth.
Through their research, scientists Scott Gahr and Caird Rexroad hope to be able to breed fish with more muscle- and therefore more edible flesh.
Indeed, if the findings bear fruit, it may well spell good news for the nation's fish industry, which, according to market researcher Mintel, is positioned to benefit from increased consumer interest as fish is an "inherently healthy" food and is also suitable for dieters.
Yet consumers need to be educated about how to prepare the product in order to benefit from the "significant opportunity to increase the frequency with which consumers eat fish and seafood," said Mintel in a 2004 report
Sales of fish and seafood are in fact forecast to grow at 21 percent at constant prices from 2004 to 2009, with frozen fish predicted to enjoy the biggest growth of 53 percent. Growth for refrigerated fish is set at 36 percent, fresh fish at 17 percent and canned fish at 15 percent.
The NCCCWA, which is part of the US Department of Agriculture's Agricultural Research Service (ARS), uses applied genetics and breeding with the aim to improve production efficiency and product quality for the cold water fish industry, which includes rainbow trout, Arctic char and striped bass.
In their latest findings, the department's researchers identified four new rainbow trout genes involved in muscle growth and development, and conducted tests for each of the genes to learn more about their specific roles.
According to their findings, the genes, known as Inhibitor of DNA Binding Differentiation (ID) genes, interact with factors present in muscle cells to delay differentiation, or the process by which cell function is defined. This increases the number of cells, say the scientists.
"Affecting the balance of these processes presents an opportunity to dictate an increase in the number of muscle cells, which would result in more edible flesh on the fish," said Gahr.
"One of our goals is to improve growth characteristics for the rainbow trout farmer through genetic selection, and these genes are clearly involved in muscle growth and development," added Rexroad.