ABSTRACT
Since its discovery, QX-type avian infectious bronchitis virus (IBV) has rapidly spread worldwide and become the most prevalent dominant genotype in Asia and Europe. Currently, although the pathogenicity of QX-type IBV in the reproductive system of hens is widely and deeply understood, its pathogenicity in the reproductive system of roosters remains largely unknown. In this study, 30-week-old specific pathogen-free (SPF) roosters were used to investigate the pathogenicity of QX-type IBV in the reproductive system after infection. The results showed that QX-type IBV infection caused abnormal testicular morphology, moderate atrophy and obvious dilatation of seminiferous tubules, and produced intense inflammation and obvious pathological injuries in the ductus deferens of infected chickens. Immunohistochemistry results showed that QX-type IBV can replicate in spermatogenic cells at various stages and in the mucous layer of the ductus deferens. Further studies showed that QX-type IBV infection affects plasma levels of testosterone, luteinizing hormone, and follicle-stimulating hormone as well as causes changes in transcription levels of their receptors in the testis. Furthermore, the transcription levels of StAR, P450scc, 3βHSD and 17βHSD4 also changed during testosterone synthesis after QX-type IBV infection, indicating that the virus can directly affect steroidogenesis. Finally, we found that QX-type IBV infection leads to extensive germ cell apoptosis in the testis. Collectively, our results suggest that QX-type IBV replicates in the testis and ductus deferens, causing severe tissue damage and disruption of reproductive hormone secretion. These adverse events eventually lead to mass germ cell apoptosis in the testis, affecting the reproductive function of roosters.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Author contributions
XZ and YW contributed to conception and design of the study. KY performed all of the experiments and wrote the first draft of the manuscript. XW and ZL provided help during the experiments. ZB, CZ, and MG provided valuable suggestions on the manuscript. All authors contributed to manuscript revision, read, and approved the submitted version.
Data availability statement
All of the data extracted for this study are included in the manuscript.