Zoccola Didier, Ganot Philippe, Bertucci Anthony, Caminiti-Segonds Natacha, Techer Nathalie, Voolstra Christian R, Aranda Manuel, Tambutté Eric, Allemand Denis, Casey Joseph R, Tambutté Sylvie
Centre Scientifique de Monaco, 8 quai Antoine Ier, Monaco, 98000, Monaco.
ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia.
Sci Rep. 2015 Jun 4;5:9983. doi: 10.1038/srep09983.
The bicarbonate ion (HCO3(-)) is involved in two major physiological processes in corals, biomineralization and photosynthesis, yet no molecular data on bicarbonate transporters are available. Here, we characterized plasma membrane-type HCO3(-) transporters in the scleractinian coral Stylophora pistillata. Eight solute carrier (SLC) genes were found in the genome: five homologs of mammalian-type SLC4 family members, and three of mammalian-type SLC26 family members. Using relative expression analysis and immunostaining, we analyzed the cellular distribution of these transporters and conducted phylogenetic analyses to determine the extent of conservation among cnidarian model organisms. Our data suggest that the SLC4γ isoform is specific to scleractinian corals and responsible for supplying HCO3(-) to the site of calcification. Taken together, SLC4γ appears to be one of the key genes for skeleton building in corals, which bears profound implications for our understanding of coral biomineralization and the evolution of scleractinian corals within cnidarians.
碳酸氢根离子（HCO3(-)）参与珊瑚的两个主要生理过程，即生物矿化和光合作用，但目前尚无关于碳酸氢根转运蛋白的分子数据。在此，我们对造礁石珊瑚鹿角杯形珊瑚中的质膜型HCO3(-)转运蛋白进行了表征。在基因组中发现了8个溶质载体（SLC）基因：5个哺乳动物型SLC4家族成员的同源物，以及3个哺乳动物型SLC26家族成员的同源物。我们利用相对表达分析和免疫染色，分析了这些转运蛋白的细胞分布，并进行了系统发育分析，以确定刺胞动物模式生物之间的保守程度。我们的数据表明，SLC4γ亚型是造礁石珊瑚特有的，负责向钙化部位供应HCO3(-)。综上所述，SLC4γ似乎是珊瑚骨骼构建的关键基因之一，这对我们理解珊瑚生物矿化以及刺胞动物中造礁石珊瑚的进化具有深远意义。
