Publication Date:
2020-02-06
Description:
Coral epithelia control ion fluxes to the calcification site influencing biomineralization and proxy incorporation. However, data on in vivo characteristics of coral tissue such as permeability, selectivity, and active ion transport are scarce but important for calcification and proxy modeling. To investigate ion permeability and ion fluxes across coral tissues in vivo, we developed an electrophysiological approach for the assessment of active and passive epithelial transport properties. Growing Stylophora pistillata corals in a thin layer over permeable filters allowed ion exchange at the site of skeleton formation for reproducible measurements of electrophysiological properties of coral tissues in a modified Ussing chamber. Compared to former applications, electrical measurements on these coral filter units were dominated by tissue characteristics with minimal influence of skeleton or physical stress. Coral tissues were cation selective. Their overall high electrical resistance characterized them as tight epithelia indicating low paracellular permeability for passive ion diffusion. This includes ions relevant for calcification. A small short-circuit current indicates active charge transport across the entire coral tissue. The present approach is applicable to corals laterally overgrowing substrates. It allows the electrophysiological characterization of coral tissue in vivo in response to environmental conditions. This will improve our knowledge on transepithelial transport relevant for biomineralization in corals.
Type:
Article
,
PeerReviewed
Format:
text
Format:
text
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