Bone Pedicle Development and its Association to the Tooth Germ in Acrodont Chameleons
| Authors | |
|---|---|
| Year of publication | 2019 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | Most lizards and snakes exhibit teeth ankylosed to the underlying bone. In chameleon the teeth are firmly attached to the top of the tooth-bearing bone pedicles (acrodont dentition). The aim of our study was to reveal the developmental processes contributing to the formation of the tooth-bone interface - what are the differences between labial and lingual parts of the bony pedicles? When is the asymmetry in bone formation lost? How is the bone translocated under the teeth? Bone pedicle initiation was analyzed by microCT in pre-hatching animals to reveal possible asymmetries in their initiation at the labial and lingual side of the lower jaw, the relation of the tooth germ to pedicle formation along the jaw, and the rearrangement of the spatial relationships between cervical loop and underlying bone. Native and iodine stained samples of several stages of chameleon embryonic jaws were scanned with GE phoenix micro CT-device, which allowed analysis of the samples in both 2D-slices and 3D-model in VG studio MAX software. TRAP-analysis was performed to detect osteoclast distribution during pedicle formations. TEM was used to analyze submicroscopic changes in cells in the area between tooth and bony pedicles. We found that chameleon teeth grew asymmetrically with higher progress on the labial part of the cervical loop at early stages. The early tooth germ at cap stage developed at a large distance from the ossification center of the mandible, and tooth and underlying bone seem to develop independently. Later in development, the cervical loop was re-oriented towards the bone ridge to meet the underlying bone. In conclusion, the acrodont dentition resembles a pleurodont dentition during development with distinct asymmetries in the cervical loop as well as early bone morphology. |
| Related projects: |