adaptive evolution of the matrix extracellular phosphoglycoprotein in mammals自适应进化的细胞外基质phosphoglycoprotein哺乳动物.pdf

Machado et al. BMC Evolutionary Biology 2011, 11:342 /1471-2148/11/342 RESEARCH ARTICLE Open Access Adaptive evolution of the matrix extracellular phosphoglycoprotein in mammals 1,2 3 3 1,4 1,3,4* João Paulo Machado , Warren E Johnson , Stephen J O’Brien , Vítor Vasconcelos and Agostinho Antunes Abstract Background: Matrix extracellular phosphoglycoprotein (MEPE) belongs to a family of small integrin-binding ligand N-linked glycoproteins (SIBLINGs) that play a key role in skeleton development, particularly in mineralization, phosphate regulation and osteogenesis. MEPE associated disorders cause various physiological effects, such as loss of bone mass, tumors and disruption of renal function (hypophosphatemia). The study of this developmental gene from an evolutionary perspective could provide valuable insights on the adaptive diversification of morphological phenotypes in vertebrates. Results: Here we studied the adaptive evolution of the MEPE gene in 26 Eutherian mammals and three birds. The comparative genomic analyses revealed a high degree of evolutionary conservation of some coding and non- coding regions of the MEPE gene across mammals indicating a possible regulatory or functional role likely related with mineralization and/or phosphate regulation. However, the majority of the coding region had a fast evolutionary rate, particularly within the largest exon (1467 bp). Rodentia and Scandentia had distinct substitution rates with an increased accumulation of both synonymous and non-synonymous mutations compared with other mammalian lineages. Characteristics of the gene (e.g. biochemical, evolutionary rate, and intronic conservation) differed greatly among lineages of t