Immunofluorescence detection of cadherins in mouse tooth germs during rootdevelopment

The distribution of two cell-adhesion molecules, E- and P-cadherin, was stu died in relation to morphological changes in Hertwig's epithelial root shea th. Before root dentinogenesis had started, the root sheath expressed both cadherins. As dentinogenesis proceeded, the sheath fragmented and lost P-ca dherin rapidly and E-cadherin slowly, whereas the intact sheath at the apic al end continued to express both. These results suggest that the two cadher ins play a part in root as well as in crown development, and indicate that the decrease in the amount of these molecules and the fragmentation of the epithelial root sheath are interrelated. (C) 1999 Elsevier Science Ltd. All rights reserved.