The Distribution Of Avain Influenza Virus And Tissue Apoptosis In Hens Oviduct Infected With H9N2Avain Influenza Virus

Low pathogenic H9N2avian influenza virus (AIV) were pandemic in poultry worldwide.The laying hens infected with H9N2AIV not only appeared histopathological lesions to therespiratory and digestive systems which lead to few death, but found reproductive systemssuch as yealding faded eggs, deformity eggs and soft shell eggs with egg production dropingprecipitously30%-80%. In such situation, huge economic losses occured in breeding layinghens industry. The autopsy of infected hens discovered the follicles deformation hemorrhageand even liquefied. Yolk peritonitis caused by broken egg yolk were appeared in abdominalcavity. Oviduct hemorrhaged and white plastic secretions were generated. Previous studieshad done mainly about the pathological lesion of AIV on poultry respiratory and digestivesystem. However, there were very few reports about the pathogenic effect of AIV on hensreproductive systems. In order to discover the pathogenic mechanism about abnormalfunction of H9N2AIV infections hens oviduct, the real-time RT-PCR was used to detect theAIV viral loads in different location in oviduct. Tissue apoptosis were detected in tissues ofH9N2AIV infections hens oviduct through TUNEL, DNA ladder analysis and Caspase-3detection. At last, the hematoxylin and eosin (HE) staining was employed to observehistologic changes of hens oviduct.1.9Hens were inoculated with H9N2by combined intraocular and intranasal route.3healthy hens were used as control group. The hens were sacrificed at3,5, and7days post-inoculation. Tissue samples of infundibulum, magnum, isthmus, uterus and vagina werecollected and preserved in liquid nitrogen promptly. AIV were detected in every section withsignificant difference of viral loads (P<0.01) in oviduct by real-time RT-PCR. The viral loadsin uterus and magnum were5.52×104±3.14×103copies/μL and5.27×104±3.55×103copies/μLrespectively, higher than others.2. TUNEL detection, DNA ladder analysis and Caspase-3enzyme activity detectionwere employed to detect tissue apoptosis in tissues of H9N2AIV infections hens oviduct. TheTUNEL detection showed that H9N2AIV could induce apoptosis in tissue of magnum,isthmus, uterus and vagina. The Caspase3enzyme activity was higher in H9N2AIVinfections hens oviduct than that in healthy hens oviduct. DNA ladder analysis foud thatH9N2AIV could induce apoptosis in tissue of magnum and isthmus. The detection of tissue apoptosis confirmed H9N2AIV could induce apoptosis in the hens oviduct. Moreover, theapoptosis were obvious in magnum, isthmus and uterus.3. HE staining found that obvious pathological changes were presented in magnum,isthmus and uterus at3,5, and7days post-inoculation. It had been fount that epithelial villusfall off and inflammator cells invasion in magnum; glands necrosis in isthmus; epithelialserosa fracture, glands necrosis and broad hemorrhage in uterus.In conclusion, this study confirmed that the viral loads in different parts of the hens oviductwere positively correlated with the pathological changes after the hens infected with H9N2AIV.