PCDH15 and Usher syndrome: The localization of Usher proteins (PCDH15 and Whirlin) as well as actin filament-related proteins in canine photoreceptors aligns with the patterns reported in NHP photoreceptors, suggesting that a canine IRD model may provide valuable insights into pathogenesis of Usher syndrome, for which effective pathological models are challenging to develop in rodents.