Wang Xiaoyan, Zhang Jiaojiao, Meng Runze, Jiang Yong, Liang Suyun, Zhang Yunsheng, Xie Ming, Zhou Zhengkui, Hou Shuisheng
Institute of Animal Sciences, Chinese Academy of Agricultural SciencesBeijing, China.
Front Microbiol. 2017 Jun 19;8:1128. doi: 10.3389/fmicb.2017.01128. eCollection 2017.
Earlier work suggested the possibility to anti duck hepatitis A virus genotype 3 (DHAV-3) using the resistance breeding strategy. Here, we report the creation of the second generations of a resistant Pekin duck flock (designated Z8R2) and a highly susceptible Pekin duck flock (designated Z8S2) and the investigation of their responses to DHAV-3. Experimental infection with DHAV-3 at 7 days of age resulted in a high mortality (66.3%) in 11 susceptible Z8S2 families and an extremely low mortality rate (2.67%) in 32 Z8R2 families, indicating that Z8R2 exhibits strong resistance to DHAV-3, while Z8S2 is highly susceptible to the virus. Detection of DHAV-3 in the liver between 1 and 60 hours post inoculation (hpi) suggests that DHAV-3 can be replicated rapidly and efficiently in the liver of Z8S2, whereas the replication of the virus in the liver of Z8R2 is suppressed greatly. High levels of serum biochemical markers (e.g., ALT, AST, ALP and GGT) were detected in Z8S2 at 24 hpi, which were significantly higher than those in Z8R2. Analysis of transcripts in the liver revealed that the expression levels of several pattern recognition receptors (PRRs) (e.g., TLR4/7, RIG-1 and MDA5) and cytokines (e.g., IL-2, IL-6, IL-8, IFN-α, and IFN-γ) in Z8S2 were significantly higher than those in Z8R2 at 12 and 24 hpi. Together these findings suggest that Z8R2 and Z8S2 Pekin ducks, which were derived from the same Z8 line, exhibit disparate pathogenic outcomes following DHAV-3 infection. Therefore, it is possible to select a Pekin duck flock resistant to DHAV-3 employing the strategy described here. It is likely that the high viral load and the strong inflammatory response correlate with the high susceptibility of Z8S2 Pekin ducks to DHAV-3.
早期研究表明，利用抗性育种策略有可能对抗鸭甲型肝炎病毒3型（DHAV-3）。在此，我们报告了第二代抗性北京鸭群（命名为Z8R2）和高易感北京鸭群（命名为Z8S2）的培育情况以及它们对DHAV-3反应的研究。7日龄时用DHAV-3进行实验性感染，导致11个易感Z8S2家系的死亡率很高（66.3%），而32个Z8R2家系的死亡率极低（2.67%），这表明Z8R2对DHAV-3表现出很强的抗性，而Z8S2对该病毒高度易感。接种后1至60小时（hpi）在肝脏中检测DHAV-3表明，DHAV-3能在Z8S2的肝脏中快速高效地复制，而该病毒在Z8R2肝脏中的复制则受到极大抑制。在24 hpi时，Z8S2中检测到高水平的血清生化标志物（如ALT、AST、ALP和GGT），显著高于Z8R2中的水平。对肝脏中的转录本分析显示，在12和24 hpi时，Z8S2中几种模式识别受体（PRRs）（如TLR4/7、RIG-1和MDA5）和细胞因子（如IL-2、IL-6、IL-8、IFN-α和IFN-γ）的表达水平显著高于Z8R2。这些发现共同表明，源自同一Z8品系的Z8R2和Z8S2北京鸭在感染DHAV-3后表现出不同的致病结果。因此，采用此处所述策略有可能选育出对DHAV-3具有抗性的北京鸭群。很可能高病毒载量和强烈的炎症反应与Z8S2北京鸭对DHAV-3的高易感性相关。
