Computational prediction of cartilage regulatory elements. Weight matrices for the SOX- and C/EBP beta binding sites were used to search functional cartilage enhancers. (A) The 183-bp Mia (mouse) element located at −2251 to −2058. (B) Col2A1 48-bp intron enhancer (mouse). (C) Col11A2 intron enhancer (mouse). (D) Mia proximal promoter (mouse). Colors represent motifs and their orientations as follows. (Blue) SOX sites on the forward strand; (red) SOX sites on the reverse strand; (green) C/EBP beta sites on the forward strand; (yellow) C/EBP beta sites on the reverse strand; (purple) overlapping SOX sites in opposite orientation. Bold letters in any color represent C/EBP beta motifs. Chondrocyte regulatory motifs containing SOX pairs and C/EBP beta are indicated by brackets. Gray shaded area in D indicates that the sequence region is conserved at >60% between human and mouse. (*) Sites mutated in transient transfections (−410m) and (−395m). T1 and T2 are statistical thresholds for C/EBP beta and SOX sites, respectively.
