S3-11 Saturday, Jan. 4 15:00 - 15:30 Dental EvoDevOmics: Novel and conserved gene expression in shark tooth development FRASER, GJ*; THIERY , A; MARTIN, KJ; JAMES, K; COOPER, RL; HOWITT, C; JOHANSON, Z; University of Florida, Gainesville; King's College, London; University of Sheffield; Natural History Museum, London; University of Sheffield; University of Sheffield; Natural History Museum, London firstname.lastname@example.org https://biology.ufl.edu/gareth-fraser/
Tooth development and subsequent dental regeneration is governed by highly conserved genetic mechanisms that are common to all toothed vertebrates. However, diversity in tooth patterning, shape and regenerative capacity is widespread. We focus on some of the most extreme forms of dental character divergence in fishes e.g. pufferfish and sharks, to appreciate the development of this diversity. We have established the shark as a model for tooth development and continued regeneration. We explore the dental transcriptome to uncover novel markers that suggest a deviation from the conserved norm of tooth development. We discovered a number of transcripts that are new to tooth development, involved in the unique and unrivalled capacity for continuous dental regeneration in sharks. We sequenced total transcripts associated with 5 distinct compartments of the shark dental lamina, an epithelial sheet from which all teeth are formed. These lamina compartments included (i) basi-hyal taste buds, (ii) the junction between taste-tooth fields, (iii) early stage developing teeth, (iv) later stage developing teeth and (v) the successional lamina, a terminal region of the dental lamina where new teeth are produced. Transcripts returned showed differentially expressed gene clusters highlighting distinct signatures associated with regeneration and stem cell niche identity. These data illuminate the unique characters of the shark dental lamina. Now we can extend our understanding of tooth regeneration more generally, and recognize how this process can become inactive, reducing regenerative ability, seen in many vertebrates.