In hermatypic scleractinian corals, photosynthetic fixation of CO2 and the production of CaCO3
are intimately linked due to their symbiotic relationship with
dinoflagellates of the Symbiodiniaceae family. This makes it difficult
to study ion transport mechanisms involved in the different pathways. In
contrast, most ahermatypic scleractinian corals do not share this
symbiotic relationship and thus offer an advantage when studying the ion
transport mechanisms involved in the calcification process. Despite
this advantage, non-symbiotic scleractinian corals have been
systematically neglected in calcification studies, resulting in a lack
of data especially at the molecular level. Here, we combined a tissue
micro-dissection technique and RNA-sequencing to identify
calcification-related ion transporters, and other candidates, in the
ahermatypic non-symbiotic scleractinian coral Tubastraea spp. Our results show that Tubastraea spp.
possesses several calcification-related candidates previously
identified in symbiotic scleractinian corals (such as SLC4-γ, AMT-1like,
CARP, etc.). Furthermore, we identify and describe a role in
scleractinian calcification for several ion transporter candidates (such
as SLC13, -16, -23, etc.) identified for the first time in this study.
Taken together, our results provide not only insights about the
molecular mechanisms underlying non-symbiotic scleractinian
calcification, but also valuable tools for the development of
biotechnological solutions to better control the extreme invasiveness of
corals belonging to this particular genus.