Meeting Abstract
Stony coral skeletal proteins, termed the ‘biomineralization toolkit’, control mineral formation and modify the mineralization milieu. To date, three coral skeletal proteomes have been sequenced, but genomic and transcriptomic data are available for many more coral species. In this study, we used a publicly available comprehensive protein reference database derived from genomic and transcriptomic data from 25 Cnidaria, including 20 stony, to understand the evolution of coral skeletal proteins. We supplemented this with recently published databases focusing on individual protein families. We also used liquid chromatography tandem mass spectrometry (LC-MS/MS) to sequence skeletal proteins from three stony corals obtained from the Natural History Museum of Los Angeles, Fungia scutaria, Pocillopora damicornis, and Porites lobata. Our phylogenetic analysis of publically available coral skeletal protein sequences suggests that one of the three classes of highly acidic skeletal proteins, SAARP2-like, evolved in complex corals after the robust-complex split ~240 Ma. In contrast, the highly acidic CARP4/SAARP1-like and acidic SOMP-like proteins are found across Scleractinia. We also show that, although corals produce many kinds of cadherins, only one, a type-III classical cadherin, is retained in coral skeleton. Finally, our in silico analysis reveals that skeletal carbonic anhydrase is quite divergent among corals. Our skeletal protein sequencing supports our phylogenetic analyses and doubles the Scleractinian genera from which such sequences have been determined. As a complete unit, our study reveals both where the ‘biomineralization toolkit’ shows consensus across Scleractinia and where clades have evolved alternative proteins.
