The candidate gene approach takes a

The candidate gene approach takes advantage of the existing knowledge of the biochemical basis of meat tenderness. As stated, current data indicate that calpainmediated proteolysis of key myofibrillar proteins is responsible for postmortem tenderization; thus, differences in the potential proteolytic activity of the calpain system result in differences in the rate and extent of postmortem tenderization. We have collected evidence indicating that, within a species, postmortem calpastatin activity is related to meat tenderness. In beef, for example, calpastatin activity at 24 hours postmortem is highly related to beef tenderness after 14 days of postmortem storage. Across species, however, at-death calpastatin activity is highly related to meat tenderness . In some special circumstances, at-death calpastatin is also related to tenderness of meat within a species such as: dietary administration of some beta-adrenergic agonists and expression of callipyge gene in lamb .