Subcellular localization of wild-type and mutant Prpf31 fusion proteins in rod photoreceptors. Wild-type and mutant Prpf31 fused to mCherry and driven by the rhodopsin promoter were transiently expressed in 7 dpf Tg(Rho:EGFP) larvae in which EGFP is stably expressed in rods and distributed throughout the cytoplasm. (A) Control mCherry was localized in the rod cytoplasm similar as EGFP. (B) Wild-type Prpf31:mCherry was localized in the nuclei of rods. (C) AD5:mCherry was mainly detected in the nuclei of rods similar to wild-type Prpf31. (D) In exceptional cases, AD5:mCherry was also observed in the cytoplasm of individual rods (arrows). Some of the AD5:mCherry positive rods show loss of the outer segment and disintegrated nuclei (arrow head) indicative for rod degeneration. (E) SP117:mCherry was aberrantly localized in the cytoplasm of rods rather than the nucleus. Morphology, however, is normal in SP117 expressing rods. ROS, rod out segment; RIS, rod inner segment; RCB, rod cell body. Left column shows EGFP channel, middle column shows mCherry channel and right column shows overlay together with DAPI stain.