Pocillopora damicornis Transcriptome or Gene expression

Reef-building corals begin as non-calcifying larvae that, upon settling, rapidly begin to accrete skeleton and a protein rich skeletal organic matrix (SOM) that attaches them to the reef. Here, we characterized the temporal expression of a suite of biomineralization genes during three stages of larval development in the reef-building coral Pocillopora damicornis: Stage I - newly released, Stage II - oral-aborally compressed, and Stage III - settled and calcifying spat. The transcriptome analysis revealed 3,882 differentially expressed genes that clustered into distinct patterns across the three developmental stages. We also identified 74 novel acidic proteins (CARPs) that are highly conserved across calcifying cnidarians, but lack detectable homologs in non-calcifying taxa. Immunolocalization supports the direct role of some CARPs in calcification. Our results give insight to the molecular basis for the developmental sequence that leads to formation of the organic scaffold of corals and the initiation of aragonite precipitation in a stony coral.