PDE6B and retinitis pigmentosa 1: The rd1 mouse model of RP exhibits early onset rod cell degeneration caused by a mutation in the Pde6b gene (Danciger et al., 1990; Pittler and Baehr, 1991; Sidman and Green, 1965), which is an ortholog of the human RP-associated PDE6B (Khramtsov et al., 1993; McLaughlin et al., 1993).