Plant, Animal & Microbe Genomes X Conference

January 12-16, 2002
Town & Country Convention Center
San Diego, CA

Workshop: Cattle/Sheep
            

BEYOND MYOSTATIN; THE SEARCH FOR INTERACTING ALLELES

¹ Department of Animal Science, Iowa State University, Ames, IA 50011

² USDA, ARS, U.S. Meat Animal Research Center, PO Box 166 Clay Center, NE, 68933-0166

Mutations in myostatin result in the double muscling phenotype in cattle. However, the molecular mechanisms whereby inactivation of myostatin results in increased skeletal muscle mass have not yet been identified. Furthermore, quantitative trait loci (QTL) have been recently identified that interact with myostatin. Thus, there is a need to identify genes that lie downstream of myostatin. To begin to address these questions, we chose to identify genes that were differentially expressed in 31 - 33 day wild type and double-muscle bovine embryos. We believe that gene that are differentially expressed in wild-type and double-muscle cattle will 1) make good candidates for genes that interact with myostatin and 2) provide insights into the molecular mechanisms whereby myostatin represses skeletal muscle growth. By suppressive subtractive hybridization, we identified numerous genes whose expression differed between double-muscled and wild type bovine embryos. Many of these genes appear to be involved in cell proliferation, transcription and protein synthesis, all of which are biological systems know to be influenced by myostatin. Furthermore, COMPASS analysis suggests that several of these genes reside within the previously identified QTL that interact with myostatin. A number of strategies are now being pursued to identify additional candidate genes and to test whether previously genes interact with myostatin.