Fine tuning of Rac1 and RhoA alters cuspal shapes by remolding the cellular geometry.
Sci Rep
; 6: 37828, 2016 11 28.
Article
in En
| MEDLINE
| ID: mdl-27892530
ABSTRACT
The anatomic and functional combinations of cusps and lophs (ridges) define the tooth shape of rodent molars, which distinguishes species. The species-specific cusp patterns result from the spatiotemporal induction of enamel knots (EKs), which require precisely controlled cellular behavior to control the epithelial invagination. Despite the well-defined roles of EK in cusp patterning, the determinants of the ultimate cuspal shapes and involvement of epithelial cellular geometry are unknown. Using two typical tooth patterns, the lophodont in gerbils and the bunodont in mice, we showed that the cuspal shape is determined by the dental epithelium at the cap stage, whereas the cellular geometry in the inner dental epithelium (IDE) is correlated with the cuspal shape. Intriguingly, fine tuning Rac1 and RhoA interconvert cuspal shapes between two species by remolding the cellular geometry. Either inhibition of Rac1 or ectopic expression of RhoA could region-distinctively change the columnar shape of IDE cells in gerbils to drive invagination to produce cusps. Conversely, RhoA reduction in mice inhibited invagination and developed lophs. Furthermore, we found that Rac1 and RhoA modulate the choices of cuspal shape by coordinating adhesion junctions, actin distribution, and fibronectin localization to drive IDE invagination.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Rac1 GTP-Binding Protein
/
RhoA GTP-Binding Protein
/
Molar
Limits:
Animals
Language:
En
Journal:
Sci Rep
Year:
2016
Document type:
Article