A mutation in α-tropomyosinslow affects muscle strength, maturation and hypertrophy in a mouse model for nemaline myopathy

Abstract

Nemaline myopathy is a hereditary disease of skeletal muscle defined by a distinct pathology of electrondense accumulations within the sarcomeric units called rods, muscle weakness and, in most cases, a slow oxidative (type 1) fiber predominance. We generated a transgenic mouse model to study this disorder by expressing an autosomal dominant mutant of α-tropomyosinslow previously identified in a human cohort. Rods were found in all muscles, but to varying extents which did not correlate with the amount of mutant protein present. In addition, a pathological feature not commonly associated with this disorder, cytoplasmic bodies, was found in the mouse and subsequently identified in human sampl..