PDE6G and retinal degeneration: The relative PDE6 protein levels were assessed by Western blotting and the rates of cGMP hydrolysis were measured in trypsin-treated retina lysates of Pde6g−/−, Pde6g−/−/Pde6ccpfl1, and C57BL/J mice (control) at P10 prior to retina degeneration.