Figure. Strategy for generation of dTGF-ß1 mice and gross tooth abnormalities in these mice. (a) Schematic representation of the TGF-ß1 transgenic construct. The transgenic construct was constructed by fusion of a 6-kb dentin sialophosphoprotein (dspp) upstream regulatory sequence with active porcine TGF-ß1 cDNA in which Cys²²³ and Cys²²⁵ codons are replaced with serine codons. (b) Normal maxillary and mandibular incisors in wild-type mice. (c) Loss of maxillary incisors (arrowhead,) and discolored and fractured mandibular incisors (arrows) in dTGF-ß1 mice. (d) Normal opacity in the craniofacial region of 15-day-old wild-type mice as measured by radiographic analysis. (e) Significantly reduced opacity in the incisors (arrows) and molars (arrowheads) of dTGF-ß1 mice. From Thyagarajan et al.(2001). With the permission of the Journal of Biological Chemistry.