Figure 1.

Alignment of opioid receptor protein sequences. (A) The protein sequences of µ (MOR) (NP_571782), δ1 (DOR1) (NP_571333) and δ2 (DOR2) (NP_997920) opioid receptors from zebrafish were aligned using the ClustalW2 program. Note that the N- and C-terminus are the least conserved regions among opioid receptors. In bold are the C-terminus sequences used to immunize rabbits. The asterisk (*) means that the residues are identical in all sequences in the alignment; the colon (:) means that conserved substitutions were observed; and the period (.) means that semi-conserved substitutions were observed. The shadow regions are transmembrane domains; (B) Alignment by pairs of the C-terminal sequences of opioid receptors from zebrafish. Note the low conservation in these sequences; (C) Alignment of the C-terminal sequences of different opioid receptors from mouse and zebrafish. Note the low conservation between the sequences of mouse and zebrafish.