Putative pheromone receptors related to the Ca ²⁺ -sensing receptor in Fugu

By a combination of PCR with degenerate primers and low stringency probing, we have isolated a large family of genes related to the Ca2+-sensing receptor from the genome of Fugu rubripes. One of the genes (type I) is the Fugu homologue of the Ca2+-sensing receptor. The remaining genes can be divided into five classes (type II-VI) on the bases of gene structure. In several types, the genes occur in clusters as tandem arrays. These genes appear to be the homologues of the vomeronasal pheromone receptors recently described in rodents. The Fugu genes are expressed in the tissues of the nose, suggesting that they may have a similar physiological role.