Fig. 5. Immunoblot of rostral and caudal arm myofibrillar homogenates revealing parvalbumin. After electrophoresis on 15 % SDS-polyacrylamide gels (A), bass MS02 (224 mm SL) rostral (A1) and caudal (A8) arm myofibrillar homogenates were transferred to nitrocellulose. Monoclonal anti-parvalbumin mouse ascites fluid PA-235 (Sigma 3171) was used to identify parvalbumin in the immunoblot (B). Normalized to actin, the densitometric value of the slower migrating parvalbumin species, parv1, is 21 % greater rostrally than caudally. The faster migrating parvalbumin species, parv2, is 25 % greater rostrally than caudally.