Involved in homophilic cell adhesion via plasma membrane adhesion molecules; retina morphogenesis in camera-type eye; and synapse assembly. Located in synapse. Is expressed in several structures, including brain; long bone; metanephros; retina nuclear layer; and ventral grey horn. Orthologous to human SDK2 (sidekick cell adhesion molecule 2). [provided by Alliance of Genome Resources, Apr 2022]