Fig. 3

Phylogenetic relationships and expression pattern of Parhyale opsins. Maximum-Likelihood tree depicting the relationships of PhOpsin1 and PhOpsin2 with the major families of pancrustacean r-opsins (see the “Materials and methods” section). Insets show the expression of PhOpsin1 and PhOpsin2 mRNA by in situ hybridization in the eyes of adult Parhyale (purple-blue colour). PhOpsin1 is expressed widely in the retina, whereas PhOpsin2 is expressed in a punctate pattern. High magnification views of individual rhabdoms (lower panels, rhabdoms stained pink) show that PhOpsin1 expression is widespread whereas PhOpsin2 expression is localised to one corner of the rhabdom. Tissue sections were stained with basic fuchsin and eosin-erythrosine. Scale bars, 10 μm