Presenter(s)

    Kyliah Gilliam-Beale

    Comments

    1:15-2:30, Kennedy Union Ballroom

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    Description

    Teeth have been maintained across most vertebrates for 400 million years, and the core regulatory network underlying tooth formation is deeply conserved in the embryonic jaws of fishes and amniotes. Unlike other vertebrates, frog odontogenesis is delayed, occurring during metamorphosis. Larval anurans possess unique keratinized mouthparts that functionally replace, and potentially inhibit, teeth. The majority of frogs form teeth on the upper jaw but lack lower jaw dentition; however, a single species re-evolved mandibular teeth. The developmental- genetic mechanisms underlying tooth formation is poorly understood in frogs, and it is unknown if an ancestral program is partially maintained in the lower jaw, providing a putative mechanism for recovering lost mandibular teeth. Using a developmental series of a non-model frog, we assessed 1) if the gene network underlying odontogenic competence is conserved in the late- forming teeth of frogs, 2) if keratinized mouthparts of tadpoles impede tooth induction, and 3) if transient tooth rudiments form in the anuran mandible. The frog upper jaw displays dental expression patterns comparable to other vertebrates, supporting the conservation of the tooth development network. Teeth emerge before keratinized mouthparts degenerate, but their location may be spatially constrained by keratin. No evidence of tooth development was found in the mandible, suggesting that frogs are unique in losing teeth without a trace. Overlapping gene expression patterns are present in tadpole keratinized mouthparts and frog teeth. We hypothesize that the novel mouthparts of tadpoles did not arise de novo but originated by partially co-opting the developmental program that typically orchestrates odontogenesis.

    Publication Date

    4-23-2025

    Project Designation

    Independent Research

    Primary Advisor

    Daniel J. Paluh

    Primary Advisor's Department

    Biology

    Keywords

    Stander Symposium, College of Arts and Sciences

    Institutional Learning Goals

    Scholarship

    Tooth Development in Frogs: Implications for the Re-Evolution of Lost Mandibular Teeth and the Origin of Vertebrate Morphological Innovation

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