乙型肝炎病毒S基因变异株的研究

目的　对７份ＨＢｓＡｇ诊断试剂检测结果不一致的样品进行确证并分析其原因。方法采用套式 ＰＣＲ法对７份样品进行ＤＮＡ扩增,并将阳性产物克隆到ｐＧＥＭ－Ｔｅａｓｙ载体上,然后进行测序并对其序列进行分析。 结果　７份样品中６份为ＨＢＶ　ＤＮＡ阳性,其中５份与Ａｂｏｏｔｔ和Ｏｒｔｈｒｏ　ＨＢｓＡｇ试剂无反应或反应较弱,而且其ａ决定 簇的氨基酸均在１３４位发生改变,由Ｆ变为 Ａ;１份与 Ａｂｂｏｔｔ和Ｏｒｔｈｒｏ ＨＢｓＡｇ试剂反应较强,其ａ决定簇的氨基酸也 在１３４位发生改变,但由Ｆ变为Ｓ。结论　国内外首次报道ＨＢｓＡｇ ａ决定簇１３４位由 Ｆ变为 Ａ后,其抗原性明显降 低,不易被ＨＢｓＡｇ试剂检出;而１３４位由对变为 Ｓ后,其抗原性无明显改变。     

甘蔗离体培养抗除草剂突变体的筛选研究简报

本试验采用桂糖11号细胞团和幼苗作离体培养，用Co^60-γ射线35Gy剂量参照后，分别转入含除草剂的培养基中，用除草剂作为选择压力，研究离体培养条件下抗除草剂突变体的筛选技术和方法。实验结果表明，经诱变培养法处理的细胞团及幼苗的存活率比经共培养法处理的高。     

Mutagenesis of Rhodobacter sphaeroides using atmospheric and room temperature plasma treatment for efficient production of coenzyme Q10

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天蚕素A-蛙皮素杂合肽突变体的构建、表达及其抗菌活性

目的构建天蚕素A(1～8)-蛙皮素(1～12)杂合基因抗菌肽(CA-MA杂合肽)突变体,在大肠杆菌中融合表达,并进行抗菌活性检测。方法采用PCR体外定点突变技术,设计1对方向相反的引物,其中1个引物引入突变点,应用高保真的PolybestDNA多聚酶进行重组表达质粒pGEX-4T-1-CA-MA的PCR扩增,使CA-MA杂合肽第16位密码子由AGT突变为TGG。将扩增片段自身连接,构建CA-MA杂合肽突变重组表达质粒pGEX-4T-1-W16-CA-MA,转化E.coliBL21,IPTG诱导表达突变体蛋白W16-CA-MA,并对表达产物进行纯化。分离GST融合蛋白后,进行抗菌活性检测。结果重组突变表达质粒DNA测序结果表明,在预期位点发生了突变;突变蛋白在大肠杆菌中的表达量约占菌体总蛋白的18%;纯化后蛋白纯度可达75%以上,并具有一定的抗菌活性。结论已成功获得了具有抗菌活性的杂合肽突变体W16-CA-MA。     

Physicochemical Characteristics of Starches of Two Sets of Near‐isogenic Wheat Lines with Different Amylose Content

Wheat lines with modified amylose content were produced by controlling the null alleles of three homoeologous Wx loci, Wx‐A1, Wx‐B1 and Wx‐D1 and those with triple‐null Wx alleles were found to yield waxy, amylose‐free starch. In this study, the new near‐isogenic lines developed by the recurrent backcross method between cv. Kanto 107 and the waxy mutant lines, K107Wx1 or K107Wx2, were cultivated and the physicochemical characteristics of their starches were investigated. The apparent amylose contents of the waxy near‐isogenic lines were 1.6 – 3.8%, whereas those of the non‐waxy near‐isogenic lines were 23.2 – 25.4%. The waxy lines had higher gelatinization temperature and enthalpy than the non‐waxy lines and no peak of amylose‐lipid complex as determined by DSC. The X‐ray diffraction patterns from both waxy and non‐waxy near‐isogenic lines corresponded to A‐type crystallization, like their parent lines. The starches isolated from the waxy lines had lower pasting onset and peak temperatures, higher peak viscosities and breakdown and lower final viscosity than those of the non‐waxy lines in the Viscoamylograph. The starch of non‐waxy near‐isogenic lines had lower peak and final viscosities and higher breakdown than did the recurrent parent line, cv. Kanto 107. The characteristics of the new wheat starches were well understood and classified, which will contribute to the wide application of these starches in food processing.     

Analysis of a Partial Male-Sterile Mutant of Arabidopsis thaliana Isolated from a Low-Energy Argon Ion Beam Mutagenized Pool

A screen for Arabidopsis fertility mutants, mutagenized by low-energy argon ion beam, yielded two partial male-sterile mutants tc243-1 and tc243-2 which have similar phenotypes. tc243-2 was investigated in detail. The segregation ratio of the mutant phenotypes in the M2 pools suggested that mutation behaved as single Mendelian recessive mutations, tc243 showed a series of mutant phenotypes, among which partial male-sterile was its striking mutant characteristic. Phenotype analysis indicates that there are four factors leading to male sterility, a. Floral organs normally develop inside the closed bud, but the anther filaments do not elongate sufficiently to position the locules above the stigma at anthesis, b. The anther locules do not dehisce at the time of flower opening （although limited dehiscence occurs later）, c. Pollens of mutant plants develop into several types of pollens at the trinucleated stage. as determined by staining with DAPI （4＇,6-diamidino-2-phenylindole）. which shows a variable size. shape and number of nucleus. d. The viability of pollens is lower than that of the wild type on the germination test in vivo and vitro.     

鞭枝藻与其突变体提取液对人膀胱癌细胞生长的影响

本文以EMS(乙基甲烷磺酸盐,Sigma)诱变嗜温的层理鞭枝藻(Mastigocladus laminosus),并经9T24C人膀胱癌细胞生长选择获得突变体。在0.3％FBS(胎牛血清) DME/F12培养液中加入100μg/ml层理鞭枝藻突变体提取液可促进9T24C癌细胞数在6天中增长3.1倍,而在同样条件下野生型层理鞭枝藻的提取液则对9T24C癌细胞无明显刺激生长作用。这种未知的刺激癌细胞生长的活性物质分子量>3500。     

CSF－1R激酶突变子的构建及其突变体在真核细胞的表达

通过ＰＣＲ二步法，构建了ｍＣＳＦ－１Ｒ激酶负性突变子，以及野生型和突变型ＣＳＦ－１Ｒ的送病毒表达载体ｐＣＥＮ／ＭＰＳＶ。进行了１２５Ｉ－ＣＳＦ－１受体结合分析：检测了激酶负性突变子，删除了ＣＳＦ－１ＲＣ－末端氨基酸９２５以后部分的突变体（ＣＴＲＵＮＣ９２５）和删除了激酶插入区的突变体（△ＫＩ）在３２Ｄ髓细胞表达。表达水平可达１～２×１０４受体／细胞。初步测定了通过ＣＳＦ－１Ｒ所介导的促细胞分裂效应。     

A群脑膜炎球菌多糖-白喉毒素无毒变异体CRM197结合物的制备及其初步评价

目的制备A群膜炎球菌多糖(Group A meningococcal polysaccharide,GAMP)-白喉毒素无毒变异体CRM197(Cross-reactive material 197)结合物,并分析其理化性质及免疫学特性。方法白喉棒状杆菌C7 M1菌株经发酵培养表达CRM197,表达产物经DEAE-4FF层析柱进行纯化,纯化产物经SDS-PAGE及Western blot鉴定。用溴化氰(CNBr)活化GAMP,己二酰肼(ADH)为连接剂,在碳二亚胺(EDAC)催化下将GAMP与CRM197共价结合,制备GAMP-ADH-CRM197结合物,经Sepharose 4FF层析柱纯化后,进行各项生化检测,采用免疫双扩散检测结合物的抗原性,将结合物皮下注射ICR小鼠,间接ELISA法检测小鼠血清中抗GAMP的抗体滴度,分析其免疫原性。结果发酵培养20 h时,菌液上清中的CRM197蛋白表达量最高;CRM197以分泌形式表达,纯化后纯度达95%以上,可与白喉类毒素单抗发生特异性反应;GAMP-ADH-CRM197结合物各项生化指标均符合《中国药典》三部(2010版)要求,与A群流脑诊断血清形成明显的沉淀线,结合物诱生的多糖特异性抗体滴度显著高于多糖组和混合物组。结论成功制备了GAMP-ADH-CRM197结合物,其具有良好的抗原性和免疫原性,为以CRM197为蛋白载体制备脑膜炎球菌结合疫苗奠定了基础。     

利用水解淀粉高产衣康酸菌株的诱变育种

利用葡萄糖产衣康酸的土曲霉为出发株,通过紫外、Co^60等诱变方法的处理,筛选得到能利用部分水解的不溶性淀粉的菌株。同时研究诱变剂的处理剂量、致死率;并进行产酸情况的测定,糖的利用率和传代稳定性的研究。最后得到几株能够高产的土曲霉菌株。其中FZ—12—4菌株产酸率达到6．30g／100ml,产酸率比出发菌株提高45％。