Morphological Variations in a Tooth Family Through Ontogeny in Pleurodeles waltl (Lissamphibia, Caudata)

摘要: Most nonmammalian species replace their teeth continuously (so-called polyphyodonty), which allows morphological and structural modifications to occur during ontogeny. We have chosen Pleurodeles waltl, a salamander easy rear in the laboratory, as model establish foundations necessary for future molecular approaches aiming understand not only processes involved tooth development replacement, but also changes, notably metamorphosis, that might usefully inform studies of morphology evolution. In order determine when (in developmental stage) how (progressively or suddenly) take place ontogeny, we concentrated our observations on single family, located at position I, closest symphysis left lower jaw. monitored replacement six first large growth series ranging from 10-day-old embryos (tooth I1) adult specimens I6), using light (LM), scanning (SEM), transmission electron (TEM) microscopy. A timetable functional period is provided teeth, compared larvae young adults. P. waltl replaced second generation forms, contrast what occurs later leading presence two 2 months life. Larval I1 shows dramatically different features I6: dividing zone has appeared between dentin cone pedicel; pulp cavity enlarged, allowing accommodation blood vessels; odontoblasts are well organized along surface; tubules dentin; become bicuspidate. these progressively one next, change monocuspid bicuspid I3 I4 transition metamorphosis. J. Morphol. © 2006 Wiley-Liss, Inc.