The phylogenetic relationship of the glutamate and pheromone G-protein-coupled receptors in different vertebrate species

Searches in genomic databases for human, mouse, zebrafish, and pufferfish genes resulted in the identification of more than 180 protein predictions belonging to the glutamate family of G-protein-coupled receptors (GPCRs). Comparison of data sets from the different species showed that most of the receptor subgroups that form the glutamate family are present in both mammalian and bony fish lineage. This finding indicates that these groups share a phylogenetically ancient origin. The present study also shows that the pheromone-receptor subgroup has undergone independent expansions in three of the four species, leaving the human genome completely deprived of all pheromone receptors.