Analysis of additional chromatin remodeling mutants reveals specificity for function in retinal development. (a–c) Transverse sections through the central retina of WT (a), baf53 mutant hi550 (b), and snf2h mutant hi1072 (c). Baf53, which has been shown to complex with Brg1, has a retinal lamination phenotype similar to yng when mutated. snf2h, which encodes the ATPase for ISWI-type chromatin remodeling complexes, shows normal retinal differentiation. (d) Summary model: Ath5 and Hedgehog (Hh) are required for retinal cell type specification, whereas the Brahma complex is required for MAP kinase activation, which is necessary for retinal differentiation and morphogenesis.
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