A note on fibre number and diameter in muscles of large and small lines of mice compared at a fixed body weight

Abstract

Summary: M. biceps brachii and m. tibialis anterior were studied at a fixed body weight in mice selected for high and low body weight at a fixed age. Muscle weights were approximately equal in the two lines. In general, muscles from high-line mice appeared to contain a larger number of smaller fibres than low-line mice in which there were fewer but wider fibres than in the unselected control population from which the lines were derived.