Fig. 5. SDS–PAGE showing parvalbumin expression in sheepshead white muscle from seven body positions ranging from 25–85% of the body length from the snout. The two isoforms are evident in all body positions. In this animal, there is a gradual increase in the relative contribution of Parv1, from 45% Parv1 at 25% of body length to 60% Parv1 at 85% of body length. There is a clear decrease in total parvalbumin expression from anterior to posterior.