New pathogenetic characters of reticuloendotheliosis virus isolated from Chinese partridge in specific-pathogen-free chickens

► Immunosuppression of infected birds is associated with apoptosis of lymphocytes. ► The 7th week post-infection is a critical time point for transformation of tumor cells. ► Squamous-cell carcinoma, adenocarcinoma and aneurysm were found in infected birds. ► Arteritis associated with concentration of serum protein and fat. ► REV has high tropism for proventriculus, kidney, liver, lymphoid tissues and pancreas.