The Novel Opsins Opn3 and 5 NonVisual Opsins Are Expressed in Cells of the Inner Vertebrate Retina. Potential Roles and Physiological Implications

RIOS, M.N.; MARCHESE, N.A.; SERRADEL, A; GUIDO, M.E.

Córdoba

Congreso; XXXIII Reunión Anual de la Sociedad Argentina de Investigación en Neurociencias; 2018

Sociedad Argentina de Neurociencias

The avian retina is composed of different types of photoreceptors responsible for image and non-image forming tasks: visual photoreceptor cells (cones and rods), the intrinsically photoresponsive retinal ganglion (ipRGCs), and horizontal cells. Nonvisual opsins Opn3 and Opn5 were shown to be expressed in the inner retina of vertebrates, responding to blue and UV light, respectively. The retina contains an endogenous circadian clock that temporally regulates itsphysiology and which is synchronized by light. To investigate expression and light regulation of Opn3 and Opn5 in the developing retina, we evaluated their expression at different embryonic (E) days and in primary cultures of neuronal and glial cells and their light responses by PCR and immunochemistry. Opn3 and Opn5 traces were detected very early in development likely in newborn RGCs, amacrine, and glial cells, and a significant increase was seen by E10 and later on. Opn3 and Opn5 were found in RGCs and Muller cell cultures by E10 and E15, respectively. In postnatal retinas, a clear light/dark difference was found in Opn3 and Opn5 proteins with higher values in the inner retina during the light phase. In addition, blue light increased expression of Opn3 in Muller cells, and it also promoted a change in its subcellular localization in neuronal cells. Results show the early appearance of these opsins during development andparticularly in inner retinal cells at the light phase suggesting an important role during the day