Figure 3
The molecular clock analysis of MC1 (open circle), MC2 (filled triangle), MC3 (open square), MC4 (asterisk) and MC5 (filled diamond) receptor subtypes. Full-length amino acid sequences were used for the calculations. The distances were calculated with Tree-Puzzle v 5.2. Lamprey MCa (open circle) and MCb (asterisk) are plotted at 564 Myr ago. We used the following divergence times from human: mouse – 90(70), chicken – 310(310), zebrafish – 450(420), dogfish – 528 (420) and lamprey – 564 (525) Myr ago. The corresponding calculated distances were plotted against molecular and fossil data for each receptor subtype separately. The lines are linear regression lines.