Skip to content. | Skip to navigation

Personal tools

Sections
You are here: Home / Lab's life / Thesis & Co / PhD defense - Ludivine BERTONNIER- BROUTY

PhD defense - Ludivine BERTONNIER- BROUTY

Dental development and replacement in Lagomorpha
When Jul 03, 2019
from 01:30 PM to 04:00 PM
Where Salle des Thèses
Contact Name Ludivine Bertonnier-Brouty
Attendees Pr. Buchtova, Marcela - Masaryk University - Rapporteure
Pr. Jernvall, Jukka - University of Helsinki - Rapporteur
Pr. Bleicher, Françoise - Université Claude Bernard - Examinatrice
Dr. Michon, Frédéric - Université de Montpellier - Examinateur
Pr. Tucker, Abigail - King’s College London - Examinatrice
Dr. Charles, Cyril – ENS de Lyon - Directeur de thèse
Dr. Joly, Thierry – ISARA Lyon - Invité
Dr. Lazzari, Vincent - Université de Poitiers - Invité
Add event to calendar vCal
iCal

Mark your calendar's for Ludivine's thesis defense entitled "Dental development and replacement in Lagomorpha". The defense will be the 3rd of July at 1:30 PM in Salle des Thèses, in English. The defense will be followed by the traditional "Pot de thèse" at the cafeteria of the third floor.

Abstract

Tooth development is essentially studied in mice, the favorite mammalian model in biology. However, mice do not replace their teeth on contrary to numerous mammals. So, the mechanisms involved in mammalian tooth replacement are still unknown. During this thesis, we focused on mammalian dental development and replacement using the European rabbit Oryctolagus cuniculus as animal model. The European rabbit is already sequenced, used in biomedical field, has a short gestation time and replaced its teeth, so rabbit seemed to be a relevant model in dental research. Rabbit dental development was not defined, so I first performed a histo-morphological study to characterize the development of deciduous and permanent teeth. 3D soft tissue reconstructions were performed at different embryonic stages to obtain a chronology of tooth development and replacement. This chronology begins with the first morphological observations of the initiation of the development of the first tooth until the mineralization of the last tooth to develop. Then, we identified in the bibliography candidate genes potentially involved in dental replacement. I studied the expression profiles of these genes in order to better understand the spatio-temporal regulation of tooth replacement in rabbits. We then returned our results to rabbit development in an evolutionary context. Thus, I performed a comparative anatomy study in the current lagomorphs and some fossils in order to identify dental morphological variations during their evolutionary history. We were particularly interested in the setting of cusps during odontogenesis as well as in the variations of the occlusal surface of the upper cheek teeth throughout the life of rabbits and other lagomorphs. Comparing changes during evolution with those observed during dental ontogeny in rabbits allow us to identify heterochronous processes of development. We have shown that the current molar rabbit follows a process of peramorphosis, so an overdevelopment compared to fossil lagomorphs. The rabbit is thus a promising animal model in developmental and evolutionary biology to better understand the implementation of mammalian tooth replacement and tooth shape variations during mammalian evolution.

 

Key words

Tooth development, mammalian dental replacement, rabbit teeth, peramorphosis, heterochrony, odontongenesis, cusp