Sample preparation for two-dimensional blue native/SDS polyacrylamide gel electrophoresis in the identification of Streptomyces coelicolor cytoplasmic protein complexes

Ammonium sulfate precipitation was tested as a sample preparation step for BN-PAGE analyses of S. coelicolor cytoplasmic protein complexes. A procedure of sample preparation compatible with two-dimensional BN/SDS-PAGE was established and used to visualize protein complexes. To validate the sample preparation procedure, representative protein complexes were identified. Several previously characterized protein complexes were rediscovered and their reported oligomeric states reconfirmed. In addition, we identified new but plausible interactions that have never been reported before. Our work provides useful reference for the wide application of BN-PAGE in protein interaction study.     

Histological alterations and immune response in the crayfish Procambarus clarkii given rVP28-incorporated diets

There is growing evidence that recombinant VP28 protein (rVP28) can significantly enhance immune response and disease resistance against white spot syndrome virus (WSSV) in shrimp, although the underlying mechanisms have not been entirely clarified yet. The aim of this study was to determine the effect of rVP28 on histological alterations and WSSV-induced apoptosis in crayfish Procambarus clarkii. Crayfish were fed commercial diets supplemented with different doses of HyNPV-VP28 infected pupae (rVP28-hp) for 4 weeks. Results showed that rVP28-hp may be used as a safe and effective source of medicinal proteins in aquaculture when supplemented in diet at low dose (10 g kg(-1) and 50 g kg(-1)), which could obviously reduce the percentage of apoptotic cells in stomach, gut and hepatopancreas tissues induced by the WSSV challenge and showed the relative percent survival (RPS) of 82.2% and 94.4%, respectively. But rVP28-hp would be detrimental to crayfish survival and decrease resistance to WSSV infection at the high dose (100 g kg(-1) and 200 g kg(-1)), with the cumulative mortality of up to 48.2% and 56.6% after WSSV challenge, respectively. During a 28-d feeding period, the survival rate of crayfish was only 54.5%-75.6%, and histopathological observation showed that one of the principal lesions was serious cell swelling, vacuolar degeneration and necrosis in hepatopancreatic epithelia and myocardial cells. These results suggested that rVP28-hp can influence the immune functions of crayfish in a dose-dependent manner, and the rVP28-hp at the dose of 50 g kg(-1) was recommended to prevent WSSV in crayfish culture.     

葡萄无核基因定位与作图的研究

以UBC 269484和GSLP1569的序列为支点,设计合成了包括UBC 269和GSLP1在内的9条引物,以葡萄 有核亲本红地球和无核亲本红光无核的DNA为模板,对这9个引物进行筛选,结果GSLP1、39970524 5号引物和 39970524 6号引物在无核亲本红光无核上扩增出了特异标记GSLP1569、39970524 5 564、39970524 6 1538和 39970524 6 1200。用这3个特异引物在红地球、红光无核、无核白和红地球×红光无核杂交组合F1代163株杂 种的DNA样上进行PCR扩增,结果4个特异标记在F1群体中与无核主效基因共分离。4个特异标记也出现于所 用组合中无核基因原始供给者无核白上。这些标记和葡萄无核主效基因相连锁。用QTXb17遗传作图软件,对葡 萄无核主效基因S定位与作图,当P=0.01时,LOD值在32.7～46.4之间,置信界限在0.2～9.9之间。这4个 特异标记和无核主效基因S处于在同一连锁群,位于无核主效基因S的两侧,覆盖基因组12.3cM。特异标记 39970524 5 564、GSLP1569、39970524 6 1538、39970524 6 1200距S基因的遗传距离分别为0.6cM、1.2cM、 4.9cM和11.1cM。     

西藏藏族人群15个短串联重复序列基因座的遗传多态性

利用多重PCR五色荧光(6FAM、VIC、NED、PET、LIZ)自动化检测技术检测西藏自治区藏族人群D8S1179、D21S11、D7S820、CSF1PO、D3S1358、TH01、D13S317、D16S539、D2S1338、D19S433、VWA、TPOX、D18S51、D5S818及FGA共15个STR基因座遗传多态性, 获得15个STR基因座的群体遗传学数据。结果显示：15个STR基因座的基因型分布符合Hardy-Weinberg平衡。15个STR基因座的个体鉴别力 (Discrimination power, DP)在0.7555~0.9602之间, 杂合度 (Heterozygosity, H)在0.5651~0.8530之间, 多态性信息含量 (Polymorphism information content, PIC)在0.5528~0.8456之间, 非父排除率(Probability of paternity exclusion, EPP)在0.3811~0.8549之间, 累积个体鉴别力为0.999999999, 累积非父排除率为0.999999998。15个短串联重复序列基因座适合作为西藏藏族人群的遗传标记, 用于人类学、疾病连锁分析、法医学亲子鉴定和个体识别等领域的研究。     

CabC, an EF-hand calcium-binding protein, is involved in Ca2+-mediated regulation of spore germination and aerial hypha formation in Streptomyces coelicolor

Ca(2+) was reported to regulate spore germination and aerial hypha formation in streptomycetes; the underlying mechanism of this regulation is not known. cabC, a gene encoding an EF-hand calcium-binding protein, was disrupted or overexpressed in Streptomyces coelicolor M145. On R5- agar, the disruption of cabC resulted in denser aerial hyphae with more short branches, swollen hyphal tips, and early-germinating spores on the spore chain, while cabC overexpression significantly delayed development. Manipulation of the Ca(2+) concentration in R5- agar could reverse the phenotypes of cabC disruption or overexpression mutants and mimic mutant phenotypes with M145, suggesting that the mutant phenotypes were due to changes in the intracellular Ca(2+) concentration. CabC expression was strongly activated in aerial hyphae, as determined by Western blotting against CabC and confocal laser scanning microscopy detection of CabC::enhanced green fluorescent protein (EGFP). CabC::EGFP fusion proteins were evenly distributed in substrate mycelia, aerial mycelia, and spores. Taken together, these results demonstrate that CabC is involved in Ca(2+)-mediated regulation of spore germination and aerial hypha formation in S. coelicolor. CabC most likely acts as a Ca(2+) buffer and exerts its regulatory effects by controlling the intracellular Ca(2+) concentration.     

Characterization of the coat protein mRNA of southern bean mosaic virus and its relationship to the genomic RNA

RNA isolated from southern bean mosaic virions contains, in small amount, a subgenomic RNA (molecular weight, 0.38 × 10⁶) that serves in vitro as an mRNA for southern bean mosaic virus coat protein. The RNA has a 5′-linked protein indistinguishable from the protein linked to the 5′ end of full-length genomic RNA. Its base sequence, determined to 91 bases from the 3′ end, is identical to the 3′-terminal sequence of the genomic RNA. The results suggest that the coat protein messenger sequence exists as a “silent” cistron near the 3′ end of the genomic RNA.     

一株对苹果树鳞翅目害虫高毒力的苏云金芽胞杆菌YX-1

苏云金芽胞杆菌Bacillus thuringiensis(Bt)YX-1是从土壤中分离的对多种鳞翅目害虫具有杀虫活性的新菌株。为了探索该菌株在果树上应用的可行性,本研究测定了Bt YX-1菌株对苹果树上6种鳞翅目害虫的杀虫毒力,同时对该菌株的晶体形态特征、蛋白型、生长特性、基因型等进行了分析。结果表明,Bt YX-1菌株产生菱形伴胞晶体,SDS-PAGE分析表明该菌株表达的主要蛋白条带分子量约为130ku和60ku;基因型鉴定表明,Bt YX-1菌株含有cry1Ac、cry2Ac、cry1I、vip3Aa和cry34-35基因;生物活性测定表明,Bt YX-1菌株的孢晶混合物对美国白蛾Hlyphantria cunea、棉铃虫Helicoverpa armigera、斜纹夜蛾Prodenia litura、梨小食心虫Grapholitha molesta、苹小卷叶蛾Adoxophyes orana以及苹掌舟蛾Phalera flavescens的LC50分别为14.48、2.72×103、6.24×104、1.01×102、3.52×104、4.73×103mg/L,均低于标准菌株Bt HD-1的LC50。发酵上清液的杀虫活性很低,2龄棉铃虫幼虫的死亡率仅为8.33%,但是该上清液能显著提高孢晶混合物的毒力,说明上清液中含有增效物质。研究结果表明该菌株具有进一步开发为商品制剂的潜力。