Comparison of laminin reorganization in primary skeletal muscle cultures grown on collagen I and synthetic matrices

Abstract

Integrins are important in the regulation of muscle development. Previous analysis of the distribution of alpha 1 integrin relative to laminin in developing chick skeletal muscle has demonstrated an early punctate cellular distribution of both proteins which later is reorganized into periodic bands found to align along the myofibril. The reorganization of both proteins is seen early in development in skeletal cultures grown on a collagen I matrix; however the reorganization is always detected subsequent to that of myofibril assembly. To ascertain whether the extracellular matrix on which the cells are plated influences the reorganization of alpha 1 integrin, primary skeletal cultures were grown on a synthetic matrix to which no additional extracellular matrix was added. Embryonic chick skeletal cultures, grown on both synthetic and collagen I matrices, were immunofluorescently labeled with antibodies to desmin, alpha-actinin, titin, C-protein, alpha 1 integrin & laminin. Cultures were examined on days 3, 5, 7 & 10. Results show that alpha 1 integrin and laminin present the same pattern of reorganization in skeletal muscle cultures grown on both the collagen and synthetic matrices. Data indicates that the reorganization of alpha 1 integrin and laminin in cultured skeletal muscle occurs independently of the matrix on which the cells are plated. Further examination of alpha 1 integrin and laminin will be necessary to determine their potential function(s) in the developmental program of skeletal muscle.