P 414 Prolonged darkness on the retinal pigment epithelium of the turtle

@r~ose. The compound eye of the honey-bee, Apis mellifera (L.), possesses retinular cells maximally sensitive to UV, blue and green wavelengths. Behavioumlly, the honey-bee exhibits trichromatic colour vision when searching for food sources and hive location. We therefore set out to sequence the opsins present in the compound eye of the honey-bee and to relate the amino acid sequences to the phylogeny and spectral tuning of the visual pigments. Methods. Opsin sequences were amplified by either conventional polymerase chain reaction (PCR) on genomic DNA, or reverse transcriptase polymerase chain reaction (RT-PCR) on mRNA extracted from heads using primers designed frbm consensus sequences of Drosophila opsins. Results. We have sequenced three opsins from the honey-bee. Two of the opsins show strong homology to the Drosophila Rhl and Rb2 opsins, while the third shows homology to the Rh4 opsin of Drosophila. Conclusions. The bee opsin showing homology to the Rh4 opsin is the outative UV oiement. whilst the oosins with seauence similaritv to ihe Rhl and&R%2 otisins are likily to be the’blue and greeh pigments. Candidate amino acids involved in spectral tuning of the opsins are identified.