The Vertebrate Tooth Row: Is It Initiated by a Single Organizing Tooth?. (29th April 2020)

• Record Type: Journal Article
• Authors: Sadier, Alexa; Jackman, William R.; Laudet, Vincent; Gibert, Yann
• Is Part Of: BioEssays. Volume 42:Number 6(2020:Jun.)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-04-29
• Subjects: dental row -- FGF evolution -- initiator -- mammals -- tooth -- zebrafish; Molecular biology -- Periodicals; Cytology -- Periodicals; Developmental biology -- Periodicals; 572.8
• DOI: 10.1002/bies.201900229
• Languages: English
• ISSNs: 0265-9247

Abstract

Abstract: Teeth are one of the most fascinating innovations of vertebrates. Their diversity of shape, size, location, and number in vertebrates is astonishing. If the molecular mechanisms underlying the morphogenesis of individual teeth are now relatively well understood, thanks to the detailed experimental work that has been performed in model organisms (mainly mouse and zebrafish), the mechanisms that control the organization of the dentition are still a mystery. Mammals display simplified dentitions when compared to other vertebrates with only a single tooth row positioned in the anterior part of the mouth, whereas other vertebrates exhibit tooth rows in many locations. As proposed 60 years ago, tooth rows can be formed sequentially from an initiator tooth. Recent results in zebrafish have now largely confirmed this hypothesis. Here this observation is generalized upon and it is suggested that in most vertebrates tooth rows could form sequentially from a single initiator tooth. Abstract : In zebrafish pharyngeal teeth, the formation of an initiator tooth is necessary and sufficient to induce the whole dental row. This initiator tooth produces instructive signals such as fgf4 that will initiate the formation of the subsequent teeth of the row. In mammals, it is hypothesized that each tooth type is initiated by an independent initiating signaling center that induces the formation of teeth of the same type. In mice, that exhibits a reduced dentition, the incisors, premolar vestigial bud, and molars would be initiated by three independent signaling centers. For the complicated relation between premolars and molars, see the full text.