Enables protein homodimerization activity. Involved in detection of light stimulus involved in visual perception. Acts upstream of or within post-embryonic retina morphogenesis in camera-type eye and retinal rod cell development. Located in photoreceptor inner segment. Is expressed in several structures, including cerebral cortex ventricular layer; ganglia; nucleus pulposus; spinal cord; and vibrissa. Used to study retinitis pigmentosa. Orthologous to human CCDC66 (coiled-coil domain containing 66). [provided by Alliance of Genome Resources, Apr 2022]