Coral calcification is intricately linked to the chemical composition of the fluid in the
extracellular calcifying medium (ECM), which is situated between the calcifying cells and the
skeleton. Here we demonstrate that the acid-base sensing enzyme soluble adenylyl cyclase
(sAC) is expressed in calcifying cells of the coral Stylophora pistillata. Furthermore,
pharmacological inhibition of sAC in coral microcolonies resulted in acidification of the ECM
as estimated by the pH-sensitive ratiometric indicator SNARF, and decreased calcification …