Adaptive evolution of myostatin in the family of Bovidae

Natural selection is fundamental to the evolution of genes. A sequence is under positive selective pressure if a particular change in a coding sequence gives an organism an advantage over other organisms. In an earlier study we have found myostatin to be a candidate for positive selective pressure in several lineages in the family of Bovidae. These changes in coding sequence suggests differences in myostatin function between cow, sheep and pig. In mammals myostatin is expressed in skeletal muscle and func tions as a negative regulator of skeletal muscle mass. In the following study of myostatin we hope to elucidate the biological effects of the substitutions in the amino acid sequence of myostatin in cow and sheep compared with pig. This is an important s tep in the understanding of the nature of the selective pressure exercised on myostatin. We would like to do this in co-operation with Professor Se-Jin Lee and his lab at Johns Hopkins University School of Medicine in Baltimore. Myostatin from cow, pig a nd sheep will be expressed in CHO cells. We will make the constructs in Bergen and express and purify the protein in Baltimore. In Bergen we also plan to prepare primary myoblast cultures, which will be transported to Baltimore and used in primary cell re porter assays, measuring the activity of myostatin from different species, with or without propeptide.