Physiol. Res. 55: 183-187, 2006

Caspase 3 Activation in the Primary Enamel Knot of Developing Molar Tooth


Laboratory of Animal Embryology, Academy of Sciences of the Czech Republic and Section of Morphology and Physiology, Veterinary and Pharmaceutical University, Brno, Czech Republic

Received February 7, 2005
Accepted April 27, 2005
On-line available May 24, 2005

Mammalian teeth develop during embryogenesis as epithelio-mesenchymal organs. The primary enamel knot is considered as a signaling center in tooth morphogenesis. After tooth bell formation, this epithelial structure undergoes apoptosis. Activation of caspase 3 represents a crucial step in the intracellular death machinery. Procaspase 3 and caspase 3 molecules were localized in the primary enamel knot of the field vole using immunohistochemistry. Different fixation procedures in cryopreserved and paraffin-embedded tissues and detection systems based on peroxidase and alkaline phosphatase mediated color reactions were applied. Apoptosis was detected using morphological criteria and the TUNEL assay. Procaspase 3 was found in both the epithelial and mesenchymal part of the tooth germ. Active caspase 3 was localized particularly in the primary enamel knot, its distribution correlated with dental apoptosis and showed a similar pattern in the field vole as in the mouse.

Key words
Apoptosis • Caspase 3 • Primary enamel knot • Tooth development

© 2006 by the Institute of Physiology, Czech Academy of Sciences