Figure 4.

Reduced Twist dosage decreases OC expression in calvaria osteoblasts. Control (Nl) and mutant (M-Tw) calvaria cells were cultured until they reached preconfluence (PC; 2 days) or confluence (C; 4 days), and the expression of osteoblast marker genes was determined. (a) Total cellular RNA was reverse transcribed and cDNA amplified by PCR to examine the expression of ALP, COLIA1, OC, or GAPDH transcripts followed by Southern blot analysis. (b) Densitometric analysis of mRNA levels was performed after correction for GAPDH (mean ± SEM of three experiments; ^AP < 0.05 vs. Nl cells).