Expression of GDNF and its receptors in developing tooth is developmentally regulated and suggests multiple roles in innervation and organogenesis

摘要: Glial cell line-derived neurotrophic factor (GDNF) is a recently identified survival for several populations of neurons in the central and peripheral nervous system that also regulates kidney development. To study roles GDNF regulation tooth innervation formation, we analyzed by situ hybridization expression patterns its receptors Ret, family receptor alpha-1 (GFRα-1), GFRα-2 from initiation first molar formation to completion crown morphogenesis. At time trigeminal axon ingrowth, mRNAs were expressed mesenchyme around germ (i.e., target field dental innervation), suggesting it involved embryonic innervation. This hypothesis was supported ability induce neurite outgrowth day 12 (E12) E15 ganglia. timing correlated with appearance Ret subset cells ganglion at E12, whereas GFRα-1 constantly during E11–E15. After birth, showed apparent correlation ingrowth presence nerve fibers tooth, papilla dentin postnatally. GFRα-1, epithelial mesenchymal stages when epithelial-mesenchymal signalling critical steps colocalized bud cap stages. Expression associated enamel knot, which putative center regulating shape. During postnatal development, mesenchyme. In addition, transcripts seen preodontoblasts odontoblasts, they may be differentiation maintenance functional properties odontoblasts. Taken together, these results suggest acts as target-derived have nonneuronal organogenetic functions Dev. Dyn. 1997; 210:463–471. © 1997 Wiley-Liss, Inc.