| As the proposed function of RGR , in a complex with 11 cis retinol dehydrogenase ( RDH 5 ) , is to regenerate 11 cis retinal under light conditions and RDH 5 is expected to function in the light independent part of the retinoid cycle , we speculated that the simultaneous loss of function of both proteins should more severely affect the rhodopsin regeneration capacity . ^^^ Here , we evaluated the role of RGR using rgr / single and rdh 5 / rgr / double knockout mice under a number of light conditions . ^^^ These and previous results suggest that RGR and RDH 5 are likely to function in the retinoid cycle , although their role is not essential and regeneration of visual pigment is only mildly affected by the absence of both proteins in rod dominated mice . . ^^^ |