摘要Subgroup J avian leukosis virus(ALV-J)is a highly oncogenic retrovirus that has been devastating the global poultry industry since the late 1990s.The major infection model of ALV-J is vertical transmission,which is responsible for the congenital infection of progeny from generation to generation.Increasing evidence has sug-gested that extracellular vesicles(EVs)derived from virus-infected cells or biological fluids have been thought to be vehicles of transmission for viruses.However,the role of EVs in infection and transmission of ALV-J remains obscure.In the present study,semen extracellular vesicles(SE)were isolated and purified from ALV-J-infected rooster seminal plasma(SE-ALV-J),which was shown to contain ALV-J genomic RNA and partial viral pro-teins,as determined by RNA sequencing,reverse transcription-quantitative PCR and Western blotting.Further-more,SE-ALV-J was proved to be able to transmit ALV-J infection to host cells and establish productive infection.More importantly,artificial insemination experiments showed that SE-ALV-J transmitted ALV-J infection to SPF hens,and subsequently mediated vertical transmission of ALV-J from the SPF hens to the progeny chicks.Taken together,the results of the present study suggested that ALV-J utilized host semen extracellular vesicles as a novel means for vertical transmission,enhancing our understanding on mechanisms underlying ALV-J transmission.