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Fig. 5 Dorsal M-cones are transformed into hybrid M/S-cones in the mouse Samd7?/? retina. (A?F) Flat mounts of adult WT and Samd7?/? mouse retina stained with S- and M-opsin antibodies demonstrate that S-opsin signal is increased throughout the dorsal region of Samd7?/? retina. (G?R) Close-up views of boxed insets from panels C and F reveal that S-opsin is up-regulated specifically in dorsal Samd7?/? M-opsin+ cones (i.e., M-cones are transformed into hybrid M/S-opsin+ cones). (S) The number of exclusively M-opsin+ cones in the dorsal Samd7?/? retina is reduced to a similar degree as the increase in the number of mixed M/S-opsin+ cones, supporting the conclusion that M-cones are transformed into hybrid M/S-opsin+ cones (mean ± SD; n = 3/genotype). (T) RNA-seq analysis of WT and Samd7?/? mouse retina demonstrates a reduction in rod-specific gene expression and an increase in cone-specific gene expression, with the exception of M-opsin (Opn1mw), which is somewhat reduced. Labeled genes were previously found to be dysregulated by qPCR analysis in another Samd7 mutant (38). Genes touching the top edge of the Volcano plot (e.g., Opn1sw) have p-adjusted values equal to zero (n = 3 retinas/genotype). Samd7minus19A mutants were used for flat-mount imaging and quantification in panels A?S. Samd7minus10A mutants were used for RNA-seq in panel T. [Scale bar in (A?F), 500 µm; Scale bar in (G?R), 20 µm.] D, V: Dorsal, Ventral. Statistical comparisons in S were performed using two-tailed, unpaired t test assuming unequal variance. **P < 0.005. SD, standard deviation.