Fig. 5.

Mammary gland morphology in control, KID and KIR female mice. (A) Mammary gland complexity was measured in female control, KID and KIR mice at 4, 8 and 16 weeks of age (for all groups, n=3–10 at 4 weeks of age, n=10–16 at 8 weeks of age and n=12–20 at 16 weeks of age). Differences between groups were measured by one-factor ANOVA. Values are presented as the mean ± s.e.m. P<0.05 was considered statistically significant. WW, control (wild-type) mice. (B) Complexity is a measure of the extent of ductal branching and was quantified using MicroSuite Basic imaging software to determine the number of intersecting branches along a line drawn midway between the leading edge of the ducts and each side of the lymph node. Broken line indicates the central line across the mammary fat pad. (C) Representative images of inguinal mammary gland whole mounts dissected from 16-week-old female control, KID and KIR mice. The glands were spread on a microscope slide and fixed in Carnoy’s solution (60% absolute ethanol, 30% chloroform, 10% glacial acetic acid) for 2–4 hours. The fat pads were then hydrated in graded ethanol solutions and placed in Carmine Alum stain overnight. They were then dehydrated in graded ethanol solutions and finally placed in xylene prior to mounting with Mount-Quick mounting medium.