A MORPHOMETRIC TECHNIQUE FOR THE HISTOLOGICAL QUANTIFICATION OF SKELETAL-MUSCLE REGENERATION

Variation in the regenerative capacity of damaged skeletal muscle betw een different strains of mice has been well documented but no precise quantitative method has been established to measure directly the pheno typic influences on muscle regeneration. We have developed such a meth od which allows clear distinction between the regenerative responses i n Quackenbush and BALB/c mice. To quantitate regeneration, crushed tib ialis anterior muscles taken from Quackenbush, BALB/c and F2 offspring 10 d postinjury were analysed morphometrically by light microscopy. M yotubes in the intermediate crush zone of transverse muscle sections w ere 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 lev el of precision and accuracy in the determination of significant diffe rences between regeneration in the different strains and in the F2 off spring. The data presented indicate that this method of quantification of skeletal muscle regeneration may be used for studies on the assess ment of the genetic basis for phenotypic variation.