Fig. 1.

Primary sequence of catfish parapinopsin aligned to chick pinopsin and selected goldfish retinal opsins. Residues conserved in all sequences are boxed. Residues similar in all sequences are shaded. Black arrowheads indicate introns present in all genes. Thehatched arrow indicates the position of the N-terminal intron found in the red/green-sensitive opsins. The gray arrowhead indicates the position of the intron found at the end of transmembrane domain 4, which is absent in parapinopsin but found in all other vertebrate opsins studied to date.