Meeting Abstract

P1.123  Friday, Jan. 4  Supersize Me: Cellular dynamics controlling size in the mammalian molar MOUSTAKAS-VERHO, JE*; CHRISTENSEN, M; KALLONEN, A; HäMäLäINEN, K; JERNVALL, J; Institute of Biotechnology, University of Helsinki; Institute of Biotechnology, University of Helsinki; Department of Physics, University of Helsinki; Department of Physics, University of Helsinki; Institute of Biotechnology, University of Helsinki Jacqueline.Moustakas@helsinki.fi

A central question in evolutionary morphology and developmental biology is how diversity in the size of structures is achieved. Mammalian molar teeth are developmentally integrated such that they form sequentially along the distally elongating dental lamina and are typically graded in size anteroposteriorly. Tooth development proceeds through a series of morphogenetic movements and signaling interactions between ectodermal epithelium and neural crest-derived mesenchyme. Evidence on mouse molar development has shown that the initiation and size of distal molars depends on previous molars through a dynamic balance between intermolar inhibition and mesenchymal activation. We compare molar development in two rodent species with similar tooth shape, but a twofold difference in size: mouse and rat. We combine this interspecies comparison with experimental evidence from transgenic mice to investigate the cellular dynamics controlling tooth size.