Fig. 7. Northern blot analysis of milk protein RNA levels in 26-week-old virgin
female mice. 28S and 18S rRNA subunits visualized by ethidium bromide
staining provided loading controls. In addition, K18
(Krt18), a luminal cell marker, was used as a positive control for
the integrity of the RNA and epithelial content. Three mice of each genotype
were examined as indicated: PR+/- (lanes 2-4),
PR+/-;
N89ß-catenin (lanes 8-10),
PR-/-;
N89ß-catenin (lanes 11-13) and
PR-/- (lanes 5-7). RNA from lactating (L, lane 14) and
virgin (V, lane 1) mice were used as positive and negative controls,
respectively.