Single-nucleus RNA sequencing illuminates a functional analog of lymphoid organ in crustacean

The presence and WSSV infection-induced aggregation of ZAP-70 positive cells in Oka of shrimp and its cytotoxic activity against heterologous cells suggest that shrimp Oka might perform similar function as the lymphoid organ in vertebrates. The present results will not only provide evidence to confirm the function of Oka in shrimp, but also greatly widen the knowledge about the origin and evolution of lymphoid organ in the animal kingdom.