A morphometric technique for the histological quantification of skeletal muscle regeneration

Variation in the regenerative capacity of damaged skeletal muscle between different strains of mice has been well documented but no precise quantitative method has been established to measure directly the phenotypic influences on muscle regeneration. We have developed such a method which allows clear distinction between the regenerative responses in Quackenbush and BALB/c mice. To quantitate regeneration, crushed tibialis anterior muscles taken from Quackenbush, BALB/c and F2 offspring 10 d postinjury were analysed morphometrically by light microscopy. Myotubes in the intermediate crush zone of transverse muscle sections were abundant in Quackenbush but sparse in BALB/c mice. In F2 offspring, regeneration responses reflected those of the parental strains, with no intermediate phenotypes. Statistical analyses indicated a high level of precision and accuracy in the determination of significant differences between regeneration in the different strains and in the F2 offspring. The data presented indicate that this method of quantification of skeletal muscle regeneration may be used for studies on the assessment of the genetic basis for phenotypic variation.