Figure 1.

Homozygous primates were shown to have nearly undetectable cone responses beginning from infancy. (A) Mean ± SEM ERG amplitudes (µV: microvolts) of both a- and b-waves from infant wildtype (n = 6), homozygotes (n = 11), and heterozygotes (n = 11) macaques was quantified and graphically depicted. Under light adapted conditions, a single flash 3.0 cd•s/m² stimulus, and a flicker (30 Hz) with the same stimulus resulted in nearly undetectable responses in homozygous macaques. Ordinary 1-way ANOVA revealed a significant interaction between genotype and amplitude at all three stimuli, F (2, 25) = 167.7, P < 0.0001, F (2, 25) = 91.70, P < 0.0001, and F (2, 25) = 82.11, P < 0.0001, respectively. Further post hoc analysis revealed a significant decrease (P < 0.0001) in homozygote infants (0.01 ± 0.3) when compared to infant wildtype (27.63 ± 1.7). No statistical significance was found between infant wildtype and heterozygotes. (B) Under light adapted conditions, a single flash 3.0 cd•s/m² stimulus of both a- and b-waves from electroretinogram amplitudes (µV: microvolts) of wildtype (n = 6), heterozygote (n = 11), homozygotes (n = 11), infants (age range = 2–11 months) and wildtype (n = 7), heterozygote (n = 9), homozygote (n = 5) adult macaques (age range = 3–16 years old) of flicker 3.0 b-wave was quantified and graphically depicted were amplitudes are presented as mean ± SEM of ERG amplitudes. Graphs show undetectable responses in infant and adult homozygotes when compared to their wildtype age groups. No statistical significance was found between age matched wildtype and heterozygote animals. Two-way ANOVA did not reveal a significant interaction between age and amplitude, F (2, 43) = 1.752, P = 0.1856. But 2-way ANOVA did reveal significance among genotype, F (2, 43) = 62.16, P < 0.0001 and among amplitude, F (1, 43) = 7.744, P = 0.0080. Data are presented as mean ± SEM. Two-way ANOVA shows a significance among genotype is present, F (2, 43) = 107.7, P < 0.0001. Tukey's post hoc analysis shows significance between wildtype and homozygote infants (P < 0.0001) and between heterozygote and homozygote infants (P < 0.0001). Similar results are seen in adult primates between wildtype and homozygotes (P < 0.0001) and between heterozygote and homozygote adults (P < 0.0001). There appears to be a mild age-related reduction in light 3.0 b-wave amplitude between heterozygote infant (121.4 ± 9.2 µV) and adult (75.9 ± 5.9 µV) macaques (P = 0.0078).