Prx1 and Prx2 cooperatively regulate the morphogenesis of the medial region of the mandibular process.
Mice lacking both Prx1 and Prx2 display severe abnormalities in the mandible. Our analysis showed that complete loss of Prx gene products leads to growth abnormalities in the mandibular processes evident as early as embryonic day (E) 10.5 associated with changes in the survival of the mesenchyme in the medial region. Changes in the gene expression in the medial and lateral regions were related to gradual loss of a subpopulation of mesenchyme in the medial region expressing eHand. Our analysis also showed that Prx gene products are required for the initiation and maintenance of chondrogenesis and terminal differentiation of the chondrocytes in the caudal and rostral ends of Meckel's cartilage. The fusion of the mandibular processes in the Prx1/Prx2 double mutants is caused by accelerated ossification. These observations together show that, during mandibular morphogenesis, Prx gene products play multiple roles including the cell survival, the region-specific terminal differentiation of Meckelian chondrocytes and osteogenesis.
Department of Craniofacial Sciences, Division of Pediatric Dentistry, School of Dental Medicine, University of Connecticut Health Center, Farmington, Connecticut 06030, USA.
Anamaria
A
Balic
Douglas
D
Adams
Mina
M
Mina
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D015415:Biomarkers / Q000378:metabolism; D002356:Cartilage / Q000033:anatomy & histology / Q000196:embryology; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation; D004622:Embryo, Mammalian / Q000033:anatomy & histology / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D005865:Gestational Age; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D017403:In Situ Hybridization; D008334:Mandible / Q000002:abnormalities / Q000033:anatomy & histology* / Q000196:embryology* / Q000378:metabolism; D008648:Mesoderm / Q000033:anatomy & histology / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D009024:Morphogenesis / Q000502:physiology*; D010012:Osteogenesis / Q000502:physiology
D015415:Biomarkers; D018398:Homeodomain Proteins; C489936:Prrx1 protein, mouse; C115469:Prrx2 protein, mouse