(A) Shh pathway activity monitored by RNA (Hand2,
Ptch1, Gli1) and by LacZ activity from a
Gli1LacZ/+ knock-in allele after
Shh removal by tamoxifen at E9.5+3h (as in Figure 1B). Mutant numbers analyzed with result shown
are indicated in each panel. Hand2 at E11.5 was very slightly
higher than Shh−/− in 1/11
Shh-CKO embryos. (B) Gli3 full-length (Gli3FL)
and repressor (Gli3R) protein quantitation in E10.5 hindlimbs, after
Bax/Bak and Shh removal as in Figure 1B,C. Blot shows representative example of Gli3 level (green) for
different genotypes (noncontiguous lanes re-ordered from same blot, indicated by
white lines). Molecular weight marker positions indicated to right; vinculin
(red) loading control. Gli3 FL/R ratios (mean + SEM)
shown at right in bar-graph with numbers analyzed (N) for each genotype. Gli3
FL/R is equivalently reduced in
Shh-CKO;Bax-CKO (p=0.00002) and in
Shh−/−;Bax-CKO
(p=0.001) compared to control, and there is no significant difference in Gli3
FL/R between Shh-CKO;BaxCKO and
Shh−/−;Bax-CKO
(p=0.48). ***, p <0.001. (C) Effect of Gli3
dosage reduction (Gli3+/−) on
Shh-CKO and on
Shh−/− skeletal phenotypes
(E16.5), compared to the effect of Bax/Bak removal
(Bax-CKO).