Twist1- and Twist2-Haploinsufficiency Results in Reduced Bone Formation
Figure 5
Reduced FGF signaling in Twist1flox/+; Twist2Cre/+ mice.
(A) Quantitative real-time PCR was performed to analyze the mRNA levels of Fgf2, Fgfr1, Fgfr2, Fgfr3 and Fgfr4, as well as two effector molecules, Erm and Pea3, using total RNA isolated from the long bones of 8-day-old control and Twist1flox/+; Twist2Cre/+ mice. The mRNA levels in the control mice were set as one, and the mRNA levels of Twist1flox/+; Twist2Cre/+ mice were expressed as folds of those in the control mice. The data represented three analyses (n = 3) for each group. (B) Immunohistochemistry showed that the level of the Fgfr2 protein (signal in brown) was reduced in the femurs of the Twist1flox/+; Twist2Cre/+ mice (right), compared to the control mice (left). (C) Immunohistochemistry showed that there was less phospho-Erk1/2 (signal in brown) than in the femurs of Twist1flox/+; Twist2Cre/+ mice, compared to the control mice. Scale bars: 100 µm.