Avian infectious bronchitis virus (IBV) infection has caused significant economic losses to the poultry industry. Unfortunately, there is currently no effective cure for this disease. Understanding the pathogenic mechanism is crucial for the treatment of the disease. Studying the pathogenic mechanism of IBV based on metabolomics analysis is helpful for identifying antiviral drugs. However, studies on metabolomics analysis of IBV infection have been relatively limited, particularly without metabolomics analysis in sera after IBV infection. In this study, 17-day-old SPF chicks were infected with the IBV GX-YL5 strain, and serum samples were collected 7 days post-infection (DPI) for metabolomics analysis using ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). A total of 143 differential metabolites were identified across 20 metabolic pathways, with the phenylalanine pathway showing the most significant changes. The level of cinnamic acid (CA), an upstream metabolite in the phenylalanine pathway, was notably increased following IBV infection. To investigate the antiviral effects of CA, chicken embryo kidney (CEK) cells and SPF chicks infected with IBV were treated with different concentrations of CA to assess its effect on viral replication. The results demonstrated that CA at 25 μg/mL effectively inhibited IBV replication in vitro; meanwhile, CA at 50 μg/mL and 25 μg/mL effectively inhibited IBV replication in vivo. Molecular docking and molecular dynamics simulation studies showed that CA interacts with the N domains of the IBV nucleocapsid (N) protein. In conclusion, the serum metabolite CA is significantly elevated following IBV infection and demonstrates remarkable antiviral effects both in vitro and in vivo, providing a promising avenue for the development of antiviral therapies to combat IBV infection.

With the emergence of new variant strains resulting from high mutation rates and genome recombination, avian infectious bronchitis virus (IBV) has caused significant economic losses to the poultry industry worldwide. Little is known about the underlying mechanisms of IBV-host interactions, particularly how IBV utilizes host metabolic pathways for efficient viral replication and transmission. In the present study, the effects of the cell membrane, viral envelope membrane, and viperin-mediated cholesterol synthesis on IBV replication were explored. Our results revealed significant increase in cholesterol levels and the expression of viperin after IBV infection. Acute cholesterol depletion in the cell membrane and viral envelope membrane by treating cells with methyl-β-cyclodextrin (MβCD) obviously inhibited IBV replication; thereafter, replenishment of the cell membrane with cholesterol successfully restored viral replication, and direct addition of exogenous cholesterol to the cell membrane significantly promoted IBV infection during the early stages of infection. In addition, overexpression of viperin effectively suppressed cholesterol synthesis, as well as IBV replication, whereas knockdown of viperin (gene silencing with siRNA targeting viperin, siViperin) significantly increased IBV replication and cholesterol levels, whereas supplementation with exogenous cholesterol to viperin-transfected cells markedly restored viral replication. In conclusion, the increase in viperin induced by IBV infection plays an important role in IBV replication by affecting cholesterol production, providing a theoretical basis for understanding the pathogenesis of IBV and discovering new potential antiviral targets.

[Objective]This paper screened out the amino acid region with good antigenicity of non-structural protein 4(nsp4)of avian infectious bronchitis virus(IBV)and prepared polyclonal antibody,so as to provide a material basis for further research on the function of nsp4 protein in the process of IBV replication and lay a foundation for the research and development of new diagnostic kits and vaccines for IBV.[Method]In this study,nsp4 protein of IBV Beaudette strain was prokaryotically expressed.Rabbit and chicken polyclonal antibodies were prepared by immunizing Japanese white rabbit and healthy negative chicken with the fusion protein nsp4 as immunogen.And the biological function of the prepared polyclonal antibodies were investigated by indirect enzyme linked immunosorbent assay(ELISA),Western blot-ting and indirect immunofluorescence assay(IFA).[Result]The nsp4 protein prokaryotic expression vector pCZN-1-HIS-nsp4 and nsp4 protein eukaryotic expression vector pVAX1-nsp4-HA were successfully constructed by selecting amino acids at positions 408-514 of nsp4 protein as prokaryotic expression sequences.The prokaryotic expression of fusion pro-tein nsp4 was 13.6 kD,which was consistent with its predicted size,and the fusion protein nsp4 was able to react with positive whole virus serum against IBV GX-YL5 and M41 strains.The serum titers of prepared rabbit and chicken poly-clonal antibodies were 1∶128000 and 1∶6400 respectively.Additionally,both polyclonal antibodies could react with the fusion protein nsp4 and IBV whole virus.Moreover,they could react with nsp4 protein expressed in chicken embryonic kidney(CEK)cells infected with IBV GX-YL5,Beaudette and M41 strains,and could react with nsp4 protein expressed in the transfected or IBV infected African green monkey kidney cells(Vero)Beaudette strain.The results of real-time fluo-rescence quantitative PCR showed that the viral loads of Vero cells increased gradually after transfection of nsp4 protein eukaryotic expression vector pVAX1-nsp4-HA.In other words,in vitro overexpressed nsp4 protein promoted IBV replica-tion.[Conclusion]Two polyclonal antibodies against nsp4 of IBV strain with high titer,good reactivity and strong speci-ficity are successfully prepared,which can be used as tools for the study of protein characteristics during cell localization and expression phase analysis.In addition,they can be used to analyze the action mechanism of nsp4 protein in the proli-feration process of IBV,and also provide reference for the study of other coronavirus nsp4 protein.

为深入研究制约棘胸蛙产业发展的主要因素,经过6年(2015—2021)对71家饲养场、153名养殖人员的调研发现,其主要制约因素为:饲料无法工业化供应(首要因素);对流水生境的依赖性;饲养周期较长;繁育技术与成本要求较高;高密度养殖时疾病防治难度大.

Infectious bronchitis (IB) virus (IBV) causes considerable economic losses to poultry production. The data on transmission dynamics of IBV in China are limited. The complete genome sequences of 212 IBV isolates in China during 1985–2020 were analyzed as well as the characteristics of the phylogenetic tree, recombination events, dN/dS ratios, temporal dynamics, and phylogeographic relationships. The LX4 type (GI-19) was found to have the highest dN/dS ratios and has been the most dominant genotype since 1999, and the Taiwan-I type (GI-7) and New type (GVI-1) showed an increasing trend. A total of 59 recombinants were identified, multiple recombination events between the field and vaccine strains were found in 24 isolates, and the 4/91-type (GI-13) isolates were found to be more prone to being involved in the recombination. Bayesian phylogeographic analyses indicated that the Chinese IBVs originated from Liaoning province in the early 1900s. The LX4-type viruses were traced back to Liaoning province in the late 1950s and had multiple transmission routes in China and two major transmission routes in the world. Viral phylogeography identified three spread regions for IBVs (including LX4 type) in China: Northeastern China (Heilongjiang, Liaoning, and Jilin), north and central China (Beijing, Hebei, Shanxi, Shandong, and Jiangsu), and Southern China (Guangxi and Guangdong). Shandong has been the epidemiological center of IBVs (including LX4 type) in China. Overall, our study highlighted the reasons why the LX4-type viruses had become the dominant genotype and its origin and transmission routes, providing more targeted strategies for the prevention and control of IB in China.

新农科要求涉农学科的建设与发展要有新思路,以适应时代和社会发展的新需求.动物学实习具有将动物学理论知识与实践相结合的特性,旧的实习模式存在经费紧缺,模式单一,实习基地建设不到位,教师专业化程度不足,学生积极性不高等方面的缺陷.基于以上问题和新农科建设的指导思想,从提升实习效果的角度出发,对动物学实习改革进行探讨.

水资源是人类及一切生物赖以生存的战略性经济资源.贵州省的水资源较为丰富,水质处于全国领先水平,可在水资源保护工作上却存在较大问题,主要体现在水资源管理不完善、利用率低、资金投入少、局部污染等方面.为了更好地保护好贵州省水资源,有必要针对当前贵州省水资源保护工作中所存在的问题采用可实现水资源持续利用的对策.

A novel avian infectious bronchitis virus (IBV) variant, designated as GX-NN160421, was isolated from vaccinated chicken in Guangxi, China, in 2016. Based on analysis of the S1 gene sequence, GX-NN160421 belonged to the New-type 1 (GVI-1) strain. More importantly, three consecutive nucleotides (AAC) deletions were found in the highly conserved structure gene N. The serotype of GX-NN160421 was different from those of the commonly used vaccine strains. The mortality of the GX-NN160421 strain was 3.33%, which contrasted with 50% mortality in the clinical case, but high levels of virus shedding lasted at least 21 days. In conclusion, the first novel IBV variant with three-nucleotide-deletion in the N gene was identified, and this unique variant is low virulent but with a long time of virus shedding, indicating the continuing evolution of IBV and emphasizing the importance of limiting exposure to novel IBV strains as well as extensive monitoring of new IBVs.

Infectious bronchitis virus (IBV) poses massive economic losses in the global poultry industry. Here, we firstly report the construction and immunogenicity comparison of virus-like particles (VLPs) carrying the S, M and E proteins (SME-VLPs); VLPs carrying the S and M proteins (SM-VLPs); and VLPs carrying the M and E proteins (ME-VLPs) from the dominant serotype representative strain GX-YL5 in China. The neutralizing antibody response induced by the SME-VLPs was similar to that induced by the inactivated oil vaccine (OEV) of GX-YL5, and higher than those induced by the SM-VLPs, ME-VLPs and commercial live vaccine H120. More importantly, the SME-VLPs elicited higher percentages of CD4+ and CD8+ T lymphocytes than the SM-VLPs, ME-VLPs and OEV of GX-YL5. Compared with the OEV of GX-YL5, higher levels of IL-4 and IFN-γ were also induced by the SME-VLPs. Moreover, the mucosal immune response (sIgA) induced by the SME-VLPs in the tear and oral swabs was comparable to that induced by the H120 vaccine and higher than that induced by the OEV of GX-YL5. In the challenge experiment, the SME-VLPs resulted in significantly lower viral RNA levels in the trachea and higher protection scores than the OEV of GX-YL5 and H120 vaccines, and induced comparable viral RNA levels in the kidneys, and tear and oral swabs to the OEV of GX-YL5. In summary, among the three VLPs, the SME-VLPs carrying the S, M and E proteins of IBV could stimulate the strongest humoral, cellular and mucosal immune responses and provide effective protection, indicating that it would be an attractive vaccine candidate for IB.

以蛋黄、土豆、南瓜、玉米、水产养殖蛙类饲料粉末、优质高档白爬宠牛蛙蝌蚪开口饲料粉末这6种食物作试验材料,探究棘胸蛙蝌蚪最喜欢吃何种食物.试验结果用SPSS17.0软件进行方差分析,结果表明蝌蚪吃蛋黄次数的数据显著高于其他5组数据(P<0.05),且其他5组食物的进食数据差异不显著(P>0.05).因此,在研制棘胸蛙蝌蚪饲料配方时,可考虑加入蛋黄以提高口感和营养.

新农科要求涉农学科的教学与改革要有新思路和新措施,以适应学科和社会发展的新需求.生物统计学具有将数理统计理论知识与实验或生产实践相结合的特性,旧的教学模式存在重数学理论教学,知识难度大,案例分析少,实际应用转化难,统计软件学习不到位,学生积极性不高等方面的缺陷.基于以上问题和新农科建设的指导思想,从提升教学效果的角度出发,对生物统计学改革进行探讨.

棘胸蛙具有很大的食用、药用和经济价值.近年来,国内棘胸蛙养殖发展较快.2015年6月至2019年6月对67个棘胸蛙养殖场进行调查,探讨棘胸蛙养殖场选址时的主要考虑因素,包括水质、温度、饲料、市场与交通、光照、安全、安全和污染防治等.实际操作过程中,还有其他如政策、民风、土地权属和水电供应等一些因素,也应在考虑范围之内.

就业前景、实验条件、课程内容、教师水平与学校学风等方面的不足，在一定程度上影响了地方院校生物类专业学生的学习积极性；探讨提高地方院校生物类专业学生学习积极性的方法。