Figure 2. RT-PCR and real-time PCR analysis of wild-type and Twist-1(+/–) animals. Total RNA was extracted and pooled from Twist-1(+/–) and Twist-1(+/+) animals of one litter at days 0, 7, and 28 for RT-PCR analysis and at D3 for quantitative real-time PCR. mRNA expression of Twist-1 in different organs. Decreased PCR product in Twist-1-deficient tissues (A). Relative gene expression of Twist-1, collagen type I (Col I), alkaline phosphatase (ALP), dentin sialophosphoprotein (Dspp), bone sialoprotein (Bsp), and osteocalcin (Oc), as observed by quantitative real-time PCR analysis in first molar organs of Twist-1(+/–) mice and wild-type littermates at post-natal D3 (B). In total, 28 molar organs/genotype/stage were used. All data are represented by mean ± standard deviation values.