Identification of multipotent dental stem cells in zebrafish, Danio rerio

Due to its capacity to replace teeth continuously throughout its life, the zebrafish, Danio rerio, provides an excellent animal model for the identification and characterization of multipotent dental stem cells in adult animals. The aim of this study is to identify the dental stem cell niche through Bromodeoxyuridine (BrdU) pulse-chase experiment, using the zebrafish animal model. During the pulse period, BrdU is incorporated into DNA of cells undergoing S-phase for DNA synthesis, and animals are removed from the BrdU solution during chase period in which the cells that divide further dilute out BrdU labels.13 Immunohistochemical (IHC) analyses using anti-BrdU of whole mount and sectioned pulse-chase specimens revealed that a 2 day pulse of 2-4 dpf embryos, followed by a 14 day chase period is long enough to dilute out detectable BrdU label in the pharyngeal teeth region. However, IHC analyses of 2 day pulse of 2-4 dpf embryos receiving a 8 day chase, revealed discrete populations of BrdU label retaining cells in the pharyngeal teeth region, that can be speculated to represent the DSC niche. Thus the results support the existence of multipotent dental stem cells that may enable the continuous replacement of zebrafish dentition.