The combined knockdown of Otx and Mitf transcription factors creates a more severe phenotype.
(A) The effect of otx1a/otx2 knockdown was compared between wildtype, mitfaw2 and mitfbhu3857 single mutants, and mitfbhu3857;mitfaw2 double mutants. Morpholinos were injected at a total concentration of 2 ng/embryo using the same needle for all genotypes. Results from one representative experiment are shown. The percentage of severe RPE defects was significantly increased (P<0.0001) in the mitfbhu3857;mitfaw2 double mutant background compared to wildtype and single mitfa and mitfb mutants. Wildtype, N = 252; mitfa, N = 196; mitfb, N = 158; mitfa;mitfb, N = 170. (B,C) At 24 hpf dct expression is nearly eliminated in mitfbhu3857;mitfaw2 embryos injected with the otx1a/otx2 morpholino combination (C) compared to sibling embryos injected with control morpholino (B).