Alteration Of The Ovalbumin Gene Expression In Oviduct Of Hens Infected With H9N2Aiv

Avian influenza (AI) H9N2virus is a low-pathogenic virus with widespread distributionin poultry in word and threatens to the poultry industry seriously.Once infected, poultry willbe dyspnoea and diarrhea, while the egg production and quality will be deteriorated—the shellof eggs turns sandy,soft and deformed as well as the egg white turns waterlike—which leadsto enormous economic losses to poultry industry.As the specific expressed product in chicken oviduct, Ovalbumin/OVA is the mainprotein in egg white with65%of the total egg white protein. OVA gene regulates the OVAexpression of eggs. However, there are no articles about OVA gene expression of chickeninfected with H9N2AIV. In the present experiment, H9N2subtype of avian influenza viruswas used for affecting nonimmune and healthy30-week old layers. By using Kjeldahl methodto determine protein content in egg white and RT-PCR to detect OVA mRNA expression, thistest studies the egg quality effected by H9N2AIV.1. We collected eggs produced by hens infected with H9N2AIV every day. By usingKjeldahl method, we determined protein content in egg whites. We found protein content inegg white of hens infected with H9N2AIV decrease from10.64%to7.21%in comparasionwith control group. Protein content of control group was10.64%; On the first day of infectedH9N2AIV, protein content was10.43%; On the second day of infected H9N2AIV, proteincontent was8.74%; From third to seventh day, protein content was7.68%,7.70%,7.65%,7.54%,7.21%respectively. This phenomenon indicated that H9N2AIV could cause proteincontent of egg white to decrease.2. We used quantitative real-time PCR to detect OVA mRNA expression in oviduct’magnum of hens infected with H9N2AIV. The result showed that on the fitst day of infectedH9N2AIV, OVA mRNA increased rapidly to11.78times than control group. On the third day,OVA mRNA decreased to1.18times than control group; On the fifth day, OVA mRNA is only0.01times than control group, On the seventh day, OVA mRNA is0.05times than controlgroup. From third to seventh day, OVA mRNA showed a tendency of rising at the beginningthen reduced.The result showed that there was a intimate correlation between the protein content in egg white and the gene expression of OVA after the laying hens got infected with subtypeH9N2of avian influenza virus.