Duck Tembusu virus induced mitophagy in vacuolate spermatogenic cells is mediated by PINK1-Parkin pathway

As a significant emerging and re-emerging pathogen in China, the widely spread of Duck Tembusu virus (DTMUV) caused enormous economic losses to poultry industry. On account of DTMUV diseases' main symptoms on haemorrhagic oophoritis, intensive attentions were focused on female reproductive organ. Nevertheless, the DTMUV infection of sperm and testis manifested that testis was an important vector for vertical transmission of DTMUV. In the present study, histopathology, immunofluorescence and transmission electron microscopy (TEM) analysis of DTMUV-infected duck testis revealed that DTMUV infection induced seminiferous epithelium injury via spermatogenic cells vacuolization. After DTMUV infection, the expression of autophagy-related genes and proteins in testis were significantly up-regulated. Further TEM analysis discovered that different stages of autophagic and mitophagy structures were visible in cytoplasm of spermatogenic cells after DTMUV infection. And more notably, the testicular protein expression of PINK1 and Parkin were significantly increased after DTMUV infection. In summary, our study discovered that, after DTMUV infection, PINK1-Parkin pathway mediated mitophagy were activated and then induced spermatogenic cells vacuolization.