Amelotin: an enamel matrix protein that experienced distinct evolutionary histories in amphibians, sauropsids and mammalsReport as inadecuate




Amelotin: an enamel matrix protein that experienced distinct evolutionary histories in amphibians, sauropsids and mammals - Download this document for free, or read online. Document in PDF available to download.

* Corresponding author 1 Evolution Paris Seine 2 Department of Biology

Abstract : Background: Amelotin AMTN is an ameloblast-secreted protein that belongs to the secretory calcium-binding phosphoprotein SCPP family, which originated in early vertebrates. In rodents, AMTN is expressed during the maturation stage of amelogenesis only. This expression pattern strongly differs from the spatiotemporal expression of other ameloblast-secreted SCPPs, such as the enamel matrix proteins EMPs. Furthermore, AMTN was characterized in rodents only. In this study, we applied various approaches, including in silico screening of databases, PCRs and transcriptome sequencing to characterize AMTN sequences in sauropsids and amphibians, and compared them to available mammalian and coelacanth sequences. Results: We showed that i AMTN is tooth enamel specific and underwent pseudogenization in toothless turtles and birds, and ii the AMTN structure changed during tetrapod evolution. To infer AMTN function, we studied spatiotemporal expression of AMTN during amelogenesis in a salamander and a lizard, and compared the results with available expression data from mouse. We found that AMTN is expressed throughout amelogenesis in non-mammalian tetrapods, in contrast to its expression limited to enamel maturation in rodents. Conclusions: Taken together our findings suggest that AMTN was primarily an EMP. Its functions were conserved in amphibians and sauropsids while a change occurred early in the mammalian lineage, modifying its expression pattern during amelogenesis and its gene structure. These changes likely led to a partial loss of AMTN function and could have a link with the emergence of prismatic enamel in mammals.

Keywords : Enamel Amelogenesis Tetrapods Bioinformatics Gene expression Evolution





Author: Barbara Gasse - Ylenia Chiari - Jérémie Silvent - Tiphaine Davit-Béal - Jean-Yves Sire -

Source: https://hal.archives-ouvertes.fr/



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