PTHrP null mutant mice exhibit skeletal abnormalities both in the craniofacial region and limbs. In the growth plate cartilage of the null mutant, a diminished number of proliferating chondrocytes and accelerated chondrocytic differentiation are observed. In order to examine the effect of PTHrP deficiency on the craniofacial morphology and highlight the differential feature of the composing cartilages, we examined the various cartilages in the craniofacial region of neonatal PTHrP deficient mice. The major part of the cartilaginous anterior cranial base appeared to be normal in the homozygous PTHrP deficient mice. However, acceleration of chondrocytic differentiation and endochondral bone formation was observed in the posterior part of the anterior cranial base and in the cranial base synchondro-ses. Ectopic bone formation was observed in the soft tissue-running mid-portion of the Meckel's cartilage, where the cartilage degenerates and converts to ligament in the course of normal development. The zonal structure of the mandibular condylar cartilage was scarcely affected, but the whole condyle was reduced in size. These results suggest the effect of PTHrP deficiency varies widely between the craniofacial cartilages, according to the differential features of each cartilage. Anat Rec 255:452-457, 1999. 1999 Wiley-Liss, Inc.
These results suggest that the potential for palate formation is maintained in the palatal shelves of GAD67(-/-) fetuses, but it is obstructed by other, probably neural, factors, resulting in cleft palate.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.