GUCA1A and Rod-cone dystrophy: From the F1 mice, heterozygous Guca1a+/COD3 and homozygous Guca1aCOD3/COD3 mutant mice were generated; in this study we present data from both mutant genotypes as the former represents a close correlate to patients with COD3, whilst the latter may provide further insights into the role that mutant GCAP1 plays in causing cone and cone-rod dystrophy.