Study Links Evolution of Stony Coral Skeleton to Bicarbonate Transporter Gene

In the Proceedings of the National Academy of Sciences, a team from the Carnegie Institution for Science, Macquarie University, and other centers in the US and Australia present findings from a comparative genomics- and gene editing-based analysis of stony coral evolution and skeleton formation, which highlighted a key role for a predicted bicarbonate transporter-coding gene called SLC4-gamma. Starting with comparative genomic analyses involving 30 stony coral family members and 15 outgroup species, together with gene expression profiling and CRISPR-Cas9-based mutagenesis, the researchers linked a tandem gene duplication in the ancestors of stony coral and other species to a newly functional SLC4-gamma gene contributing to skeleton-related calcium carbonate formation in juvenile coral. "Taken together, the results suggest that the evolution of the stony corals involved the neofunctionalization of the newly arisen SLC4-gamma for a unique role in the provision of concentrated bicarbonate for calcium-carbonate deposition," they report. "The results also demonstrate the feasibility of reverse-genetic studies of ecologically important traits in adult corals."