Proliferation and apoptosis in early molar morphogenesis - voles as models in odontogenesis

Abstract

Proliferation and apoptosis play crucial roles in the development of multicellular organisms. Their precise balance is necessary for tissue homeostasis throughout life. The developing dentition is a suitable model to study proliferation and apoptosis during embryogenesis, but the corresponding studies have been carried out principally in the mouse. The present study aimed to examine proliferation and apoptosis in the vole (Microtus sp., Rodentia) during the early morphogenesis of the first upper molar and compare it to what is known from the mouse. To this end, apoptosis and proliferation were investigated using histology and computer-aided 3D reconstruction. Mitoses accumulated predominantly in the developing cervical loop. Apoptosis during early odontogenesis showed highly specific spatio-temporal patterns in the dental epithelium. Apoptotic bodies were localised in non-dividing cell populations. They accumulated in the same places as described in the mouse: antemolar vestiges (ED 12.5 -15.5), enamel knot (ED 14.5 -15.5), stalk and palatally along the whole first molar tooth germ longitudinal axis (ED 15 -15.5). Early tooth development in the field vole, including the distribution of apoptosis and mitosis, is very similar to that reported in the mouse, with the exception of the antemolar region. The microtine antemolar vestige is preserved longer than the murine one. It is conceivable that additional distinct differences in morphogenetic processes appear later in tooth development.

Apoptotic Signaling in Mouse Odontogenesis

“…Apoptosis has been observed in early morphogenesis, as well as during hard tissue formation and during tooth eruption (Matalova et al, 2004). A comprehensive study of the temporospatial distribution of apoptosis in prenatal mouse molar development was provided by Lesot et al (1996), followed by a prenatal comparison in the field vole by Setkova et al (2006). Apoptosis during postnatal stages of tooth-bone interactions in the mouse first molar was recently reported by Lungova et al (2011) and in the mouse third molar by Chlastakova et al (2011).…”

Morphological modularity and assessment of developmental processes within the vole dental row (Microtus arvalis, Arvicolinae, Rodentia)

“…Common vole teeth (Microtus arvalis) were chosen for this study, as tooth design in voles is suitable for the recognition of numerous morphological traits. Although mouse studies are more numerous, the vole is also a well-studied model, contributing greatly to knowledge of rodent cheek tooth development (e.g., Kera¨nen et al 1998;Salazar-Ciudad and Jernvall 2002;Matalova et al 2005;Witter et al 2005;Setkova et al 2006). Several hypotheses have been presented to describe the modular organization of molars within the dentition (for an exhaustive review concerning tooth modular organization, see Stock 2001).…”

Evolution of Mammal Tooth Patterns: New Insights From a Developmental Prediction Model

“…Cement is present inside the reentrant angles of the triangles. These are reasons why vole molars have increasingly been used as a parallel model to improve our knowledge of rodent cheek tooth development (e.g., Keränen et al 1998; Jernvall et al 2000a; Salazar‐Ciudad and Jernvall 2002; Matalova et al 2005; Witter et al 2005; Setkova et al 2006). Furthermore, voles are considered, among terrestrial mammals, as good models to study evolutionary mechanisms and they account for one of the most widely diversified mammal groups of the Quaternary (Chaline 1972; Chaline and Mein 1979; van Kolfschoten 1990; Fejfar and Repenning 1992; Nadachowski 1992; von Koenigswald 1992; van Kolfschoten 1992; Sesé 1995; Montuire and Desclaux 1997; Montuire et al 1997; Montuire 1999; Montuire and Marcolini 2002).…”