Meeting Abstract
Many reptiles replace their teeth continuously, providing an opportunity to understand the process of tooth renewal. We present preliminary data from a longitudinal study of tooth replacement in adult leopard geckos (Eublepharis macularius). Upper jaw wax impressions revealed dynamic patterns of tooth shedding and limited midline symmetry. Typically, a tooth is shed in one week and replaced by a functional tooth within the next week. Across all tooth positions during the 14 week control period, the average replacement frequency is once every 6.5 weeks with a range of never replacing to immediate replacement after one week. The cycle of replacement for a given tooth position was not constant over time, but spatial and temporal data show some periodicity. Although the periodic spacing of shed teeth within a functional tooth row differs between individuals, there is a pattern across the row over time that individuals share and may reflect mechanisms of physiological or developmental control within the tooth row. These waves of replacement occur along the jaw and usually last for 5-6 replacements. Replacement in E. macularius shows more rapid turnover than similar patterns reported for Iguana iguana and Alligator mississippiensis. The regularity of the observed patterns suggest emergent replacement phenomena that may result from the order of tooth initiation between tooth families, local inhibitory influences within the jaw, and the rates of development within tooth families. Studies are currently underway to assess the influence of each of these factors. As such, the leopard gecko serves as an ideal model to investigate the molecular underpinnings of classical hypotheses such as the Zahnreihen and local inhibition models for reptilian tooth replacement.
