试验旨在探究多个地方品种快慢羽鸡的内源性病毒基因21(ev21)以及SPEF2基因与PRLR基因的部分重复序列(JS序列)分布对羽速基因(Kk)表型的影响.采用PCR扩增、HaeⅢ限制性内切酶酶切的方法检测不同地方品种快慢羽鸡性染色体上OR区域(ev21占据片段)、UR区域(URa、URb(ev21未占据片段))以及JS序列分布情况.结果表明:国内的一些地方品种部分慢羽鸡个体OR区域ev21基因缺失以及部分快羽鸡的URb区域存在ev21基因插入;可通过JS序列扩增对快慢羽表型进行准确鉴定.研究结果显示JS序列可作为快慢羽鉴定候选基因,该方法可广泛应用于国内快慢羽鸡种的鉴定.

Based on the RNA-seq data of chicken spleen tissues infected with J subgroup avian leukosis virus (ALV-J), we found that prolactin (PRL) gene was one of differentially expressed gene. We measured ALV-J viremia and PRL levels in the plasma of two groups of ALV-J-infected adult chickens. Furthermore, recombinant chicken PRL (cPRL) was used to assess how cPRL affects ALV-J virus replication both in vivo and in vitro. The results showed that PRL levels in the plasma of adult chickens infected with ALV-J were lower than those of uninfected chickens, and that the difference was more significant in the avian leukemia pathological apparent changes. Notably, the fluctuations in PRL levels might influence the disappearance of ALV-J viremia in chickens. The in vitro results showed that preincubating DF-1 cells with cPRL before ALV-J infection elicited the best antiviral effects. Moreover, these effects were not dose-dependent. in vivo, injection of cPRL into ALV-J-infected chicks could reduce the levels of viremia at the 14 days post infection (dpi). Additionally, the expression of the interferon-stimulated genes oligoadenylate synthetase-like (OSAL) and vasoactive intestinal peptide (VIP) increased, and that of the proinflammatory cytokine-encoding TNTα, IL-1β, and IL-6 genes decreased in the spleens of ALV-J-infected chicks injected with cPRL, leading to inhibition of viral replication at the 7 dpi. Collectively, our data demonstrated that PRL plays an important antiviral role in the immune response to ALV-J infection. This is the first report of the relationship between ALV-J infection and PRL. It is of great significance for the prevention and control of ALV-J.

Cytokine-inducible Srchomology2 (SH2)-containing protein (CIS) belongs to the suppressors of cytokine signaling (SOCS) protein family function as a negative feedback loop inhibiting cytokine signal transduction. J subgroup avian leukosis virus (ALV-J), a commonly-seen avian virus with a feature of immunosuppression, poses an unmeasurable threat to the poultry industry across the world. However, commercial medicines or vaccines are still no available for this virus. This study aims to evaluate the potential effect of chicken CIS in antiviral response and its role on ALV-J replication. The results showed that ALV-J strain SCAU-HN06 infection induced CIS expression in DF-1 cells, which was derived from chicken embryo free of endogenous avian sarcoma-leukosis virus (ASLV) like sequences. By overexpressing CIS, the expression of chicken type I interferon (IFN-I) and interferon-stimulated genes (ISGs; PKR, ZAP, CH25H, CCL4, IFIT5, and ISG12) were both suppressed. Meanwhile, data showed that CIS overexpression also increased viral yield. Interestingly, knockdown of CIS enhanced induction of IFN-I and ISGs and inhibited viral replication. Collectively, we proved that modulation of CIS expression not only affected SCAU-HN06 replication in vitro but also altered the expression of IFN-I and ISGs that act as an essential part of antiviral innate immune system. Our data provide a potential target for developing antiviral agents for ALV-J.

为了解广东地方品种鸡J亚群禽白血病病毒(ALV-J)净化情况,利用ALV-p27特异性抗原检测、病毒分离、PCR扩增和全基因组测序分析等方法,从广东某地方品种鸡群中分离鉴定出1株ALV-J,命名为GDYH-Y1.全基因组序列分析表明,GDYH-Y1分离株的LTR、gag和pol基因相对保守,而3'UTR和gp85基因变异较大,其中gp85基因与ALV-J参考毒株序列同源性仅为87.5％～92.8％,3'UTR区的rTM出现大量碱基缺失,遗传进化分析表明GDYH-Y1分离株与美国白羽肉鸡源分离株ADOL-7501亲缘关系最近.研究为广东地方品种鸡ALV-J净化效果提供数据参考,为分析广东地方品种鸡ALV-J毒株的分子特征和变异趋势提供了重要的数据资料.

The avian leukosis virus subgroup J (ALV-J) belongs to the chicken retrovirus that causes enormous economic losses in the poultry industry. Interferon-stimulated genes (ISGs) are critical for controlling virus infections. Here, we identified 897 type I ISGs induced by interferon-α (IFN-α) in chicken peripheral blood mononuclear cell (PBMC) by RNA-Seq. In addition, we further identified 152 potential anti-ALV-J chicken type I ISGs. Among these potential anti-ALV-J ISGs, chicken cholesterol 25-hydroxylase (chCH25H) was selected for further antiviral mechanism studies in chicken embryo fibroblast cell lines (DF1). The gene chCH25H is located on chromosome 6 and clustered in a distinct group with mammals CH25H in the phylogenetic tree. The core promoter region of chCH25H was located within −75/−1 sequence. We found that chCH25H was induced by chicken IFN-α and ALV-J in DF1 cells. The overexpression of chCH25H significantly inhibited ALV-J replication in DF1 cells at 48 h post infection (hpi). In addition, ALV-J replication was significantly enhanced in the chCH25H- knockout DF1 cells. Furthermore, we demonstrated that chCH25H restricted ALV-J infection through the production of 25-hydroxycholesterol (25HC), rather than type I and II interferon. Our results identified 152 potential anti-ALV-J chicken type I ISGs and revealed that 25HC, the product of chCH25H, could be used as a natural antiviral agent to control ALV-J infection.

为了解胡须鸡中是否存在禽白血病病毒（ALV）感染,从广东某胡须鸡养殖场中无菌采集胡须鸡血样,采用DF-1细胞培养、ELISA抗原检测、PCR扩增等方法,成功分离鉴定出一株J亚群禽白血病病毒（ALV-J）,命名为GDHX01株。测序结果显示GDHX01株病毒基因组DNA序列全长为7616 bp,gp85基因全长919 bp。通过与其他禽白血病病毒参考毒株的基因组DNA序列进行比对分析,发现GDHX01与国内外J亚群禽白血病参考毒株同源性85.3%～95.7%之间。进一步比对发现,GDHX01毒株的gp85基因序列与国内外ALV-J参考株CAUGX01的同源性最高为95.8%。结果表明,在胡须鸡群中存在J亚群禽白血病病毒的感染。