Study on transgenic mice growing into craniofacial anomaly

Abstract

In order to elucidate the genetic effects on the growth and development of craniofacial regions, HIV-1 transgenic mice (TG mice) which exhibited the phenotype of anterior crossbites were investigated by various methods. Northern hybridization showed that the introduced gene was expressed from 14.5 days post coitum to adult. In morphological measurements using digital converter "GRADICON", significant differences between TG mice and wild type mice (WT mice) were found at 5 weeks of age (5W) for most measurement items. Especially at 7W, the results indicated remarkable reductions in maxilla and catch up growth in the mandible. On the other hand, the serum alkaline phosphatase activity of TG mice (3W, 5W, and 7W) was significantly higher than that of WT mice, and also the low level of inorganic phosphate was detected at 3W for TG mice. These results suggested that TG mice had a disorder of bone metabolism. Other TG mouse lines carrying the same DNA construct showed normal figures in the craniofacial regions, suggesting the possibility that the phenotype of anterior crossbites and the disorder of bone metabolism were not caused by functions of HIV-1 genome but by insertional mutation in craniofacial development.