Fig. 5.

Novel opsin isoforms in squid and their expressions across tissues. (A) Maximum-likelihood tree, based on amino-acid sequences of opsins. The best maximum-likelihood tree was inferred using RAxML with the GTR evolutionary model and 1000 bootstrap replicates. Idiosepius and Nautilus opsins are shown in red. The cephalopod opsins are clustered in three groups; rhabdomeric opsins, retinochromes, and invertebrates’ ciliary opsins. Bootstrap support values are shown in the circles at the nodes (Red, 100%; black, 100–80%; gray, 80–50% of 1000 repetitions). (B) Gene-expression patterns of Idiosepius opsins across tissues. (C) Gene-expression patterns of Nautilus opsins across the tissues.