Miniaturization: How many cells are needed to build a tooth?. Issue 7 (25th January 2021)

• Record Type: Journal Article
• Authors: Larionova, Daria; Lesot, Hervé; Huysseune, Ann
• Is Part Of: Developmental dynamics. Volume 250:Issue 7(2021)
• Page Start: 1021
• Page End: 1035
• Publication Date: 2021-01-25
• Subjects: convergent extension -- dental papilla -- medaka (Oryzias latipes) -- odontoblast; Morphogenesis -- Periodicals; Anatomy -- Periodicals; Anatomie -- Périodiques; Biologie du développement -- Périodiques; 571.833
• DOI: 10.1002/dvdy.300
• Languages: English
• ISSNs: 1058-8388

Abstract

Abstract: Background: Organs that develop early in life, and are replaced by a larger version as the animal grows, often represent a miniature version of the adult organ. Teeth constituting the first functional dentition in small‐sized teleost fish, such as medaka ( Oryzias latipes ), are examples of such miniature organs. With a dentin cone as small as the size of one human cell, or even smaller, these teeth raise the question how many dentin‐producing cells (odontoblasts) are required to build such a tooth, and whether this number can be as little as one. Results: Based on detailed observations with transmission electron microscopy (TEM) and TEM‐based 3D‐reconstructions, we show that only one mesenchymal cell qualifies as a true odontoblast. A second mesenchymal cell potentially participates in dentin formation, but only at a late stage of tooth development. Moreover, the fate of these cells appears to be specified very early during tooth development. Conclusions: Our observations indicate that in this system, one single odontoblast fulfills roles normally exerted by a large and communicating cell population. First‐generation teeth in medaka thus provide an exciting model to study integration of multiple functions into a single cell. Key Findings: With a size of one human cell, medaka first‐generation teeth are an example of extreme miniaturization of a vertebrate organ. Only one single cell qualifies as true dentin‐producing cell, fulfilling roles normally exerted by a large and communicating cell population. First‐generation teeth in medaka thus provide an exciting model to study integration of multiple functions into a single cell.