Species differences in 5-HT2A receptors: cloned pig and rhesus monkey 5-HT2A receptors reveal conserved transmembrane homology to the human rather than rat sequence.

Pig and rhesus monkey 5-HT2A receptor cDNA clones were isolated. The pig and rhesus monkey clones encode proteins that share a 94% and 95% homology, respectively, with the rat 5-HT2A receptor, and a 97% and > 99% homology, respectively, with the human 5-HT2A receptor. Within the transmembrane regions of the pig and monkey receptors, the deduced amino acid shows only three differences compared to that of the rat and are identical to the human 5-HT2A receptor clone.