Caspase 3 Activation in the
Primary Enamel Knot of Developing Molar Tooth
E. MATALOVÁ, F. KOVÁŘŮ, I. MÍŠEK
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
Summary
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
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