Publication Date:
2018-04-03
Description:
Nonmammalian tooth-bearing vertebrates usually replace their teeth throughout life. Much about how a replacement pattern is generated has
been learned from zebrafish. However, to understand general mechanisms of tooth replacement, advantage can be taken from studying other, “nonmodel” species. We have mapped the patterns of tooth replacement in
widely divergent aquatic osteichthyans using 2D charts, in which one axis is time, the other linear spacing along the tooth row. New teeth that are generated simultaneously are considered part of the same odontogenic wave. Using this approach, it appears that a similar, general pattern underlies very distinctive dentitions in distantly related species. A simple shift in spacing of odontogenic waves, or in distance between subsequent tooth positions along a row (or both), can produce dramatically different
dentitions between life stages within a species, or between closely related species. Examples will be presented from salmonids, cyprinids, and cichlids. Our observations suggest that lines linking subsequent positions may have more biological significance than replacement waves (usually linking alternate positions), often used to explain the generation of patterns. The
presence of a general pattern raises questions about common control mechanisms. There is now increasing evidence, at least for the zebrafish, to support a role for stem cells in continuous tooth renewal and control of replacement patterns.
Type:
Article
,
NonPeerReviewed
Format:
text
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