Fig. 2.
N89ß-catenin expression induces alveolar
development. Immunohistochemistry demonstrating expression of casein in
alveoli from endogenous Rag1-/- (A) and
transplanted PR-/-;
N89ß-catenin (B)
glands at 14.5 days of pregnancy. Arrows point to luminal secretions
containing casein. Immunohistochemical analysis demonstrating high levels of
NKCC1 expression in young wild-type virgin (C) and transplanted
PR-/- (D) glands at 14.5 days of pregnancy. Low
levels of NKCC1 expression are observed in alveoli (arrowheads) generated in
PR-/-;
N89ß-catenin (E) and endogenous
Rag1-/- (F) glands at p14.5. Insets show higher
magnifications of the boxed areas and demonstrate NKCC1 expression along the
basolateral cell borders of ductal cells (insets in C,D) and absence of NKCC1
staining in alveoli (insets in E,F). (G) An example of the criteria
used to identify primary ducts, secondary branches and side-branches.
(H) Table of the number of secondary and side-branches observed per
1000 pixels of ductal length in PR+/- (n=7
fields), PR+/-;
N89ß-catenin (n=4
fields), PR-/- (n=7 fields) and
PR-/-;
N89ß-catenin glands (n=6
fields). Differences in side-branches are statistically significant between
PR+/- and PR-/- glands
(P=0.008) and PR+/-;
N89ß-catenin and
PR-/-;
N89ß-catenin glands (P=0.003),
but not between PR-/- and
PR-/-;
N89ß-catenin glands (P=0.057).
Scale bars: 50 µm.