非结构蛋白在非洲猪瘟病毒感染中作用

非洲猪瘟(African swine fever,ASF)是由非洲猪瘟病毒(African swine fever virus,ASFV)感染引起的一种急性、出血性猪传染病,给疫情发生国家(地区)的养猪业造成重大经济损失.ASFV为双股DNA病毒,基因组含有150～167个开放阅读框(ORFs),可编码150～200种蛋白质,其中非结构蛋白有100余种.ASFV编码的酶、转录因子、调节宿主细胞功能蛋白和病毒免疫逃逸相关蛋白等作为重要的非结构蛋白,在病毒核苷酸代谢、DNA复制、修复、转录、蛋白修饰以及病毒与宿主细胞相互作用等过程中发挥重要作用,但仍有许多非结构蛋白的功能尚不明晰.因此,本文综述了 ASFV非结构蛋白在病毒感染中的作用,以期为ASFV非结构蛋白的进一步研究提供参考.     

Genetic Analysis of Human Adenovirus Type 7 Strains Circulating in Different Parts of China

To investigate the molecular epidemiology and genetic variation of human adenovirus type 7(HAdV-7) in children with acute respiratory infections(ARI) in China. HAdV-7-positive respiratory samples collected from children with ARI in Beijing, Shijiazhuang, Wenzhou and Guangzhou from 2014–2018 were selected for gene amplification and sequence analysis. Fifty-seven HAdV-7 clinical strains with hexon, penton base and fiber gene sequences were obtained. Meanwhile17 strains were selected randomly from different cities for whole genome sequencing. Phylogenetic and variation analyses were performed based on the obtained sequences, HAdV-7 prototype strain Gomen(AY594255), vaccine strains(AY495969 and AY594256) and representative sequences of strains. The phylogenetic trees constructed based on whole genome sequences, major capsid protein genes(hexon, penton base and fiber) and the early genes(E1, E2, E3 and E4) were not completely consistent. The HAdV-7 strains obtained in this study always clustered with most of the circulating strains worldwide from the 1980 s to the present. Compared with the HAdV-7 prototype strain Gomen(AY594255), some amino acid mutations in loop1 and loop2 of hexon and the RGD loop region of the penton base gene were observed. Recombination analysis showed that partial regions of 55 k Da protein and 100 kDa hexon-assembly associated protein genes among all HAdV-7 strains in this study were from HAdV-16 and HAdV-3, respectively. Our study demonstrated the molecular evolution characteristics of HAdV-7 strains circulating in China and provided basic reference data for the prevention, control and vaccine development of HAdV-7.     

Flu Universal Vaccines: New Tricks on an Old Virus

Conventional influenza vaccines are based on predicting the circulating viruses year by year, conferring limited effectiveness since the antigenicity of vaccine strains does not always match the circulating viruses. This necessitates development of universal influenza vaccines that provide broader and lasting protection against pan-influenza viruses. The discovery of the highly conserved immunogens(epitopes) of influenza viruses provides attractive targets for universal vaccine design. Here we review the current understanding with broadly protective immunogens(epitopes) and discuss several important considerations to achieve the goal of universal influenza vaccines.     

聚多曲霉菌原生质体和液泡的制备及优化

原生质体的大量制备是研究原生质体转化、诱变、融合等技术的关键,液泡的制备对研究液泡中分解、转运有机物的特性具有重要意义,但目前分离技术还不够成熟.本研究从聚多曲霉菌菌丝中分离原生质体和液泡并对分离条件进行优化,以聚多曲霉菌DJ515-2菌丝为材料,探索不同因素对原生质体和液泡制备分离效果的影响.结果表明,聚多曲霉菌DJ515-2在菌龄42 h,以3％纤维素酶、1％蜗牛酶和3％的溶壁酶组成复合酶液,25℃下酶解4 h,原生质体达到最大产量,为5.167×105个/mL.同时,在此基础上裂解液泡的最优条件为pH7.5、1.0mol/L KCl、0.020％Triton X-10,其产量达2.63×105个/mL,产率为原生质体的50.8％,相比采用多元碱化合物诱导真菌原生质体裂解释放液泡的产率增加了 40％～45％.本研究为真菌和植物的各种原生质体技术及基于亚细胞层面的研究提供了材料基础.     

北盘江大峡谷流域浮游生物资源调查及多样性分析

为探究北盘江大峡谷流域内浮游生物群落组成及多样性情况,于2017年10月对该流域进行浮游生物调查及多样性分析.结果表明该流域内浮游植物共有7门40属61种、其中绿藻门、硅藻门和蓝藻门种类分别为21种、19种和12种,分别占到34.43％、31.15％和19.67％,浮游植物平均密度为4 298.33(375～9 500)ind./L,Shannon-Wiener藻类生物多样性指数均处于1和2之间;浮游动物3门12属21种,其中轮虫类、枝角类和桡足类种类分别为11种、5种和5种,各占到52.38％、23.81％和23.81％,浮游动物平均密度为436.11(55～1 437.5)ind./L,Shannon-Wiener生物多样性指数均处于1和2之间.本研究结果该地区水生生物资源积累了本底资料.     

杧果蔗糖合成酶MiSS基因的克隆与表达分析

为克隆杧果(Mangifera indica L.)蔗糖合成酶基因序列,预测其编码蛋白特性,阐明其在果实发育过程中的表达规律和作用.本研究采用同源克隆法和RACE技术克隆了1个编码蔗糖合成酶基因的全长cDNA,命名为MiSS,其cDNA全长2110 bp,开放阅读框为1455 bp,编码484个氨基酸,相对分子量为55.3 kD,理论等电点为6.08.系统进化分析显示,MiSS基因编码的氨基酸序列与温州蜜柑(Citrus unshiu)、荔枝(Litchi chinensis)、龙眼(Dimocarpus longan)氨基酸序列一致性为90％～93％.RT-qPCR分析显示,MiSS基因表达量呈现先上升后下降的趋势,且果实发育各时期果皮内MiSS基因表达量均显著高于果肉,综合分析MiSS基因可能与淀粉的合成密切相关.本研究为进一步了解MiSS基因在杧果蔗糖代谢过程中的作用以及从分子角度阐明植物生长调节剂对杧果蔗糖代谢的影响机理奠定了理论和技术基础.     

外泌体提取及保存技术研究进展

外泌体是多种活细胞经过"内吞–融合–外排"等一系列过程主动向胞外分泌的纳米级双层膜结构小囊泡,广泛存在于血液和尿液等生物体液中。因其携带着多种蛋白质、核酸和脂质等生物活性分子,所以外泌体不仅在细胞间物质交换和信息传递中发挥重要作用,而且对疾病诊断、预后预测和治疗管理等均具有提示意义。外泌体的高效提取、分离和完整保存是研究其在机体内生物学作用和功能的重要前提,也是制约基于外泌体的临床检测技术和治疗载体技术的关键。该综述将针对目前国内外外泌体提取和保存领域的最新研究进展加以综述,并对其特点进行对比和分析,以促进外泌体研究方法的标准化,以及相关技术的研发和应用拓展。     

Analysis of methylparaben in cosmetics based on a chemiluminescence H2O2−NaIO4−CNQDs system

In this article, a simple, effective chemiluminescence (CL) method for the detection of methylparaben (MP) in cosmetic samples was developed based on an IO₄^?–H₂O₂–carbon nitrogen quantum dots (CNQDs) system without a separation process. The results indicated that the redox reaction between periodate and hydrogen peroxide released hydroxide radicals and superoxide radical anions in the presence of bicarbonate. These two radicals were responsible for the formation of excited luminophor CNQD* with a maximum wavelength at 480 nm. Due to the competitive reaction with hydroxide radicals, CL intensity was markedly diminished in the presence of MP. The relative standard deviation in the intraday assay was below 5.5% (n = 9), and the detection limit was as low as 0.50 μmol/L. The proposed method allowed for the successful, selective determination of MP in cosmetics.     

CX3CL1 promotes tumour cell by inducing tyrosine phosphorylation of cortactin in lung cancer

It has been reported that chemokine CX₃CL1 can regulate various tumours by binding to its unique receptor CX₃CR1. However, the effect of CX₃CL1-CX₃CR1 on the lung adenocarcinoma and lung squamous cell carcinoma is still unclear. Here, we showed that CX₃CL1 can further invasion and migration of lung adenocarcinoma A549 and lung squamous cell carcinoma H520. In addition, Western blot and immunofluorescence test indicated CX₃CL1 up-regulated the phosphorylation level of cortactin, which is a marker of cell pseudopodium. Meanwhile, the phosphorylation levels of c-Src and c-Abl, which are closely related to the regulation of cortactin phosphorylation, are elevated. Nevertheless, the src/abl inhibitor bosutinib and mutations of cortactin phosphorylation site could inhibit the promotion effect of CX₃CL1 on invasion and migration of A549 and H520. Moreover, these results of MTT, Hoechst staining and Western blot suggested that CX₃CL1 had no effect on the proliferation and apoptosis of A549 and H520 in vitro. The effects of CX₃CL1 were also verified by the subcutaneous tumour formation in nude mice, which showed that it could promote proliferation and invasion of A549 in vivo. In summary, our results indicated that CX₃CL1 furthered invasion and migration in lung cancer cells partly via activating cortactin, and CX₃CL1 may be a potential molecule in regulating the migration and invasion of lung cancer.