Abstract
The relation between area and DNA content of the mammary gland was investigated using C3H/He and C57BL/6 strains of virgin mice 50 to 230 days after birth in order to study whether mammary gland area (MGA) measured with the whole mount preparation can be used as an index of mammary gland development. Correlation coefficients were calculated in the pooled data of certain ages according to the phase of mammary gland development. In C3H/He mice, significant correlations were obtained in the 50 to 70 and the 170 to 230 day-old age groups, but not in the 90 to 150 day-old group. In C57BL/6 mice, there were significant correlations not only in the 50 to 90 day-old group but also in the 110 to 210 day-old group, the coefficient being larger in the former. The present results revealed that MGA would be a fairly good index of quantitative development of the mammary gland during the sharp growing phases of the gland, especially of the duct system.
