海伦脑炎微孢子虫分泌蛋白EhPTP4对宿主内质网蛋白降解通路的调控作用

【目的】微孢子虫是一类专性细胞内寄生的真核病原微生物,能够感染人类和几乎所有的动物。本课题以海伦脑炎微孢子虫（Encephalitozoon hellem）为研究对象,探讨其极管蛋白4（EhPTP4）作为一个潜在的分泌性毒力因子在宿主细胞内的定位和功能。【方法】制备EhPTP4的鼠源多克隆抗体,利用间接免疫荧光分析和Western blotting确定EhPTP4在感染细胞中的亚细胞定位;基于序列特征,在HEK293细胞中转染野生型和突变体EhPTP4,分析该蛋白的定位及其对病原增殖的作用;利用RNA-seq对转染EhPTP4的HEK293细胞进行转录组测序,分析EhPTP4引起的宿主基因表达和通路的变化;进一步通过RNAi和细胞转染分析差异表达基因的调控作用,利用RT-qPCR和Western blotting验证调控效果。【结果】EhPTP4的N端具有信号肽,C端具有富含组氨酸的结构域（HRD）和核定位信号序列（NLS）。蛋白定位分析显示,在感染和转染细胞中,EhPTP4均被分泌至宿主细胞核内。在HEK293细胞中过表达EhPTP4显著促进了病原的增殖。RNA-seq和蛋白泛素化分...     

渤海海域渤东凹陷沙河街组四段古生物组合的发现及其意义

渤海海域渤东凹陷沙河街组四段内发现了丰富的孢粉、藻类和轮藻类化石组合,孢粉组合与渤海湾沿岸地区沙河街组四段的E phedri pites-Ulmoidei pites tricostatus-Pterisis porites组合特征一致,沟鞭藻类见有Luxadinium elongatum,Cangaianella e...     

Impacts of fish aggregation devices on size structures of skipjack tuna Katsuwonus pelamis

Tuna purse seine fisheries target fish aggregated in schools, including free schools that are formed naturally based on fish biology and aggregations associated with natural and/or artificial drifting objects. Using data collected from skipjack tuna (Katsuwonus pelamis) fisheries, we evaluated differences in size structures between drifting-floating-object-associated schools and unassociated schools. We developed a generalized linear model to remove impacts of environmental variables on skipjack size composition. This study indicates that the drifting-floating-object-associated schools tended to have significantly wider size ranges than the unassociated schools. This suggests that unassociated schools were likely formed based on similarity in sizes among individuals within a school while drifting-floating-object-associated schools were probably composed of individuals of large size ranges and their formation was not based on the “size selection” rule. We concluded that the unassociated schools and the drifting-floating-object-associated schools were formed through different mechanisms, and drifting floating objects could aggregate unassociated schools of different size structures. Thus, a large scale of deployment of man-made floating objects might disrupt the spatial aggregation pattern of fish that otherwise tended to school based on their sizes in the absence of floating objects.     

凝结芽胞杆菌BC01对白羽肉鸡生产性能、免疫器官指数及肠道大肠埃希菌的影响

为研究在饲料中添加凝结芽胞杆菌BC01对白羽肉鸡生产性能、免疫器官指数及肠道大肠埃希菌的影响,将240只白羽肉鸡随机分为4组,试验组1、试验组2、试验组3在饲料中添加凝结芽胞杆菌BC01的终浓度分别为1×10~8、2×10~8、3×10~8 cfu/kg,对照组日粮中不添加任何微生态制剂,饲养6周。结果显示,日粮中添加凝结芽胞杆菌BC01可显著提高肉鸡平均日增重(P0.05),显著降低料重比(P0.05),降低死淘率(P0.05),胸腺指数、法氏囊指数均显著高于对照组(P0.05),降低肠道中的大肠埃希菌数量。结果表明,日粮中添加凝结芽胞杆菌BC01,对肉鸡的生长性能有一定的促进作用,提高饲料转化率,提升肉鸡的免疫力,提高肉鸡饲养的经济价值。凝结芽胞杆菌BC01的最佳添加浓度为每公斤饲料添加2×10~8 cfu/kg。     

Cryo-EM structure of glycoprotein C from Crimean-Congo hemorrhagic fever virus

Crimean-Congo hemorrhagic fever virus (CCHFV) is a causative agent of serious hemorrhagic diseases in humans with high mortality rates. CCHFV glycoprotein Gc plays critical roles in mediating virus-host membrane fusion and has been studied extensively as an immunogen. However, the molecular mechanisms involved in membrane fusion and Gc-specific antibody-antigen interactions remain unresolved largely because structural information of this glycoprotein is missing. We designed a trimeric protein including most of the ectodomain region of Gc from the prototype CCHFV strain, IbAr10200, which enabled the cryo-electron microscopy structure to be solved at a resolution of 2.8 ?. The structure confirms that CCHFV Gc is a class II fusion protein. Unexpectedly, structural comparisons with other solved Gc trimers in the postfusion conformation revealed that CCHFV Gc adopted hybrid architectural features of the fusion loops from hantaviruses and domain III from phenuiviruses, suggesting a complex evolutionary pathway among these bunyaviruses. Antigenic sites on CCHFV Gc that protective neutralizing antibodies target were mapped onto the CCHFV Gc structure, providing valuable information that improved our understanding of potential neutralization mechanisms of various antibodies.     

Efficient assembly of a large fragment of monkeypox virus genome as a qPCR template using dual-selection based transformation-associated recombination

Transformation-associated recombination (TAR) has been widely used to assemble large DNA constructs. One of the significant obstacles hindering assembly efficiency is the presence of error-prone DNA repair pathways in yeast, which results in vector backbone recircularization or illegitimate recombination products. To increase TAR assembly efficiency, we prepared a dual-selective TAR vector, pGFCS, by adding a P_ADH1-URA3 cassette to a previously described yeast-bacteria shuttle vector, pGF, harboring a P_HIS3-HIS3 cassette as a positive selection marker. This new cassette works as a negative selection marker to ensure that yeast harboring a recircularized vector cannot propagate in the presence of 5-fluoroorotic acid. To prevent pGFCS bearing ura3 from recombining with endogenous ura3-52 in the yeast genome, a highly transformable Saccharomyces cerevisiae strain, VL6-48B, was prepared by chromosomal substitution of ura3-52 with a transgene conferring resistance to blasticidin. A 55-kb genomic fragment of monkeypox virus encompassing primary detection targets for quantitative PCR was assembled by TAR using pGFCS in VL6-48B. The pGFCS-mediated TAR assembly showed a zero rate of vector recircularization and an average correct assembly yield of 79% indicating that the dual-selection strategy provides an efficient approach to optimizing TAR assembly.     

Development of a fluorescent probe hydrolysis-insulated isothermal PCR for rapid and sensitive on-site detection of African swine fever virus

Highlights
1. A probe-based insulated isothermal PCR (iiPCR) assay was developed for rapid and onsite detection of ASFV.
2. The developed iiPCR showed similar sensitivity and specificity with OIE recommended real-time PCR.
3. Blood samples could be directly applied as PCR template in iiPCR without DNA extraction.     

GenoBaits Soy40K: a highly flexible and low-cost SNP array for soybean studies

<正>Dear Editor,Soybean(Glycine max [L.] Merr.) provides more than half of the oilseeds and more than a quarter of protein worldwide. It is estimated that the production of soybean has to be doubled by 2050 to meet the needs of the rapidly increasing consumption of soybean seeds along with a continuously increasing population(Ray et al., 2013). As such, development of a genotyping platform with high throughput, high efficiency and high precision but low-cost is urgently needed to accelerate...     

广东省徐闻县药用植物资源调查

采用代表区域－样地－样方套－样方及样线调查的方法,通过野外调查、标本采集与鉴定等对广东省徐闻县药用植物资源的种类进行研究。结果表明,该县有药用植物100科469种,其中重点种类56种,广东省特色中药资源28种。野生药用植物资源的蕴藏量极少,应加强对资源的保护。