Dear MARMAMers, We are pleased to announce the following publication:
Evidence of Positive Selection of Aquaporins Genes from Pontoporia blainvillei during the Evolutionary Process of Cetaceans<http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0134516> São Pedro SL, Alves JMP, Barreto AS, Lima AOdS (2015) Evidence of Positive Selection of Aquaporins Genes from Pontoporia blainvillei during the Evolutionary Process of Cetaceans. PLoS ONE 10(7): e0134516. doi: 10.1371/journal.pone.0134516 Published: July 30, 2015 Abstract Marine mammals are well adapted to their hyperosmotic environment. Several morphological and physiological adaptations for water conservation and salt excretion are known to be present in cetaceans, being responsible for regulating salt balance. However, most previous studies have focused on the unique renal physiology of marine mammals, but the molecular bases of these mechanisms remain poorly explored. Many genes have been identified to be involved in osmotic regulation, including the aquaporins. Considering that aquaporin genes were potentially subject to strong selective pressure, the aim of this study was to analyze the molecular evolution of seven aquaporin genes (AQP1, AQP2, AQP3, AQP4, AQP6, AQP7, and AQP9) comparing the lineages of cetaceans and terrestrial mammals. Our results demonstrated strong positive selection in cetacean-specific lineages acting only in the gene for AQP2 (amino acids 23, 83, 107,179, 180, 181, 182), whereas no selection was observed in terrestrial mammalian lineages. We also analyzed the changes in the 3D structure of the aquaporin 2 protein. Signs of strong positive selection in AQP2 sites 179, 180, 181, and 182 were unexpectedly identified only in the baiji lineage, which was the only river dolphin examined in this study. Positive selection in aquaporins AQP1 (45), AQP4 (74), AQP7 (342, 343, 356) was detected in cetaceans and artiodactyls, suggesting that these events are not related to maintaining water and electrolyte homeostasis in seawater. Our results suggest that the AQP2 gene might reflect different selective pressures in maintaining water balance in cetaceans, contributing to the passage from the terrestrial environment to the aquatic. Further studies are necessary, especially those including other freshwater dolphins, who exhibit osmoregulatory mechanisms different from those of marine cetaceans for the same essential task of maintaining serum electrolyte balance. The paper is open access at the link above. Sincerely, André Barreto ________________________________ Dr. André S. Barreto Website: http://libgeo.acad.univali.br<http://libgeo.acad.univali.br/> Google Scholar Profile<http://scholar.google.com.br/citations?user=w-2Z_jUAAAAJ> / ResearchID<http://www.researcherid.com/rid/A-7707-2010> Lab. de Informática da Biodiversidade e Geoprocessamento Setor D6, Sala 215 / CTTMar, UNIVALI R. Uruguai, 458 - CEP 88302-901 - Itajaí/SC - Brasil Fone: 47-33417960 - FAX: 47-33417715
_______________________________________________ MARMAM mailing list [email protected] https://lists.uvic.ca/mailman/listinfo/marmam
