Meeting Abstract

P1.144  Sunday, Jan. 4  Cloning and Characterization of Crustacean Calcium-Sensing Receptors (CaSRs) HOLM, C.; KEACH, S.; BETKA, M.; HARRIS, H.W.; JURY, S.H.*; MariCal Inc.; MariCal Inc.; MariCal Inc.; MariCal Inc.; MariCal Inc. sjury@marical.biz

Many marine invertebrates experience significant changes in the ionic composition of environments they encounter during their life histories. In terrestrial animals and fish, G-protein coupled receptors called calcium-sensing receptors (CaSRs) have been identified as key regulators of ionic and nutrient homeostasis. Recent genome projects, including those for Ciona intestinalis and Strongylocentrotus purpuratus, have suggested CaSR gene homologs are present in invertebrates (Loretz, 2008) but their possible tissue specific expression is unknown. We report here the cloning of a full-length CaSR gene from the lobster Panulirus interruptus (LobCaR), and compare it to other known or putative CaSRs. Using CaSR specific antibodies we also demonstrate the existence of CaSRs in other crustaceans. The gene structure and sequence are highly conserved relative to CaSRs from mammals and teleosts. Studies using anti-LobCaR antibodies reveal that crustacean CaSRs are expressed predominantly in osmoregulatory and calcium regulating tissues including antennal gland, gill, and gastrointestinal tract. We conclude that CaSRs are expressed in lobsters and likely play an integral role in multiple physiological functions in crustaceans including nutrient and salinity sensing, calcium homeostasis and biomineralization.