The visual pigment xenopsin is widespread in protostome eyes and impacts the view on eye evolution

In this study, we provide clear evidence that xenopsin enters cilia in the eye of the larval bryozoanTricellaria inopinata and triggers phototaxis. As reported from a mollusc, we find xenopsin coexpressed with rhabdomeric-opsin in eye photoreceptor cells bearing both microvilli and cilia in larva of the annelidMalacoceros fuliginosus. This is the first organism known to have both xenopsin and ciliary opsin, showing that these opsins are not necessarily mutually exclusive. Compiling existing data, we propose that xenopsin may play an important role in many protostome eyes and provides new insights into the function, evolution, and possible plasticity of animal eye photoreceptor cells.
Source: eLife - Category: Biomedical Science Tags: Evolutionary Biology Neuroscience Source Type: research