盐碱胁迫对红车轴草种子萌发的影响

以红车轴草种子为试材,利用不同浓度的NaCl溶液、NaHCO_3溶液、NaCl和NaHCO_3(1∶1)混合溶液在培养皿中模拟3种盐碱环境,观察红车轴草种子的萌发状况,以期明确红车轴草的耐盐碱能力。结果表明:红车轴草种子发芽率、发芽势、相对发芽率、发芽指数、活力指数、苗鲜重和胚根长等指标,表现出随NaCl、NaHCO_3、NaCl和NaHCO_3混合溶液(1∶1)浓度的增加,总体呈下降趋势。苗鲜重和胚根长,呈现显著的负相关关系,相对盐害率与溶液浓度呈现正相关关系。NaCl胁迫下红车轴草种子萌发的耐盐浓度8.091‰,半数抑制浓度10.146‰,极限浓度12.200‰;NaHCO_3胁迫下红车轴草萌发的耐盐浓度5.483‰,半数抑制浓度7.434‰,极限浓度9.386‰;NaCl与NaHCO_3(1∶1)混合溶液胁迫下红车轴草萌发的耐盐浓度6.081‰,半数抑制浓度7.253‰,极限浓度8.425‰。蒸馏水复萌试验表明,经3种盐碱胁迫后红车轴草种子均有不同程度的复萌。综上所述,红车轴草种子具有一定的抗耐盐碱能力。     

Kisspeptin-10对蛋鹌鹑卵巢发育与内分泌的影响

为研究Kisspeptin-10(Kp-10)对禽类生殖内分泌的影响,将75羽22日龄雌鹌鹑随机分为3组,分别腹腔注射300μL生理盐水(对照组),注射0.1 nmol Kp-10(低剂量组)和1 nmol Kp-10(高剂量组),每日注射1次,连续注射3周。记录鹌鹑开产情况,并于60日龄时采集血液和卵泡组织,测定生殖激素与受体的mRNA表达。结果:与对照组相比,注射Kp-10组鹌鹑产蛋率显著提高,且大卵泡数显著增加,血液中雌激素水平显著升高;低剂量组输卵管重显著增加,但体重、肝脏重和小卵泡重无显著变化。Real-time PCR结果显示,Kp-10处理显著下调小卵泡及F1级卵泡上促黄体激素受体(LHR)、促卵泡激素受体(FSHR)和促性腺激素释放激素Ⅰ(GnRH-Ⅰ)的基因表达。     

油乳剂疫苗中硬脂酸铝含量与油相水相比例关系研究

进行了鸡新城疫、传染性支气管炎、产蛋下降综合征三联油乳剂疫苗生产中降低油相比例的试验.当油乳剂疫苗的油相中硬脂酸铝含量分别为2%、1%、0.5%,对应的油相:水相分别为3:1、2:1和1:1时进行的乳化试验结果表明:随着油相中硬脂酸铝含量降低,油相和水相的比例相应降低,呈正比例关系.当油相中硬脂酸铝含量与油/水比分别为2%和3:1、1%和2:1、0.5%和1:1时,制备的油苗质量均达到了国家标准.     

Pathogenic specialization in Melampsora epitea var. epitea on Salix

Eighteen isolates of the rust fungus Melampsora from different locations in England were tested for pathogenicity to a large range of willow clones ( Salix spp.) in experiments involving inoculation of leaf discs. Seventeen of the isolates were of leaf-infecting M. epitea var. epitea , 16 of which represented forms which alternated on Larix and one of which alternated on Ribes . The remaining isolate was of uncertain identity. Two experiments were carried out. In the first experiment, 24 willow clones consisting of 20 Salix species and interspecific hybrids were inoculated with eight isolates from clones of S. viminalis . In the other experiment, 77 clones from 57 species or hybrids were inoculated with 10 isolates from several Salix spp. The M. epitea var. epitea isolates from S. viminalis clones were all similarly pathogenic, whilst most of the other isolates expressed distinct host specificity. Eight distinct pathotypes were recognized within M. epitea var. epitea . All except one of these alternated on Larix and could be assigned to three formae speciales which had been reported previously in Europe: four pathotypes to f.sp. larici-epitea typica , two to f.sp. larici-retusae , and one to f.sp. larici-daphnoides . The Ribes -alternating pathotype of M. epitea var. epitea infected only S. purpurea . Nine differential willow hosts are proposed as reference clones to distinguish between the larch-alternating pathotypes, the Ribes -alternating rust and the 'stem-infecting' form. The extent of pathogenic variation encountered amongst sexually reproducing rusts suggests that more pathotypes probably exist and will arise in future in response to selection given by long-term clonal willow plantings.     

猪IL-18基因的原核表达及重组蛋白的纯化

以pcDNA3．1-pIL-18为模板，采用PCR技术扩增到了猪白细胞介素18（IL-18）的成熟蛋白基因，通过KpnⅠ＋SacⅠ双酶切及连接反应，构建了pET32c—pIL—18原核表达质粒。经过限制性内切酶分析、PCR鉴定及DNA序列测定证实，重组质粒中的基因片段连接正确。之后，重组质粒转化大肠杆菌BL21（DE3），于37℃、1．0mmol／L IPTG条件下诱导表达。菌体裂解产物经SDS—PAGE分析，在分子质量约为33ku处出现了预期的目的蛋白。用8mol／L脲对表达产物变性，经Ni^2＋NTA柱纯化，透析复性，得到了纯化的IL-18蛋白。Western—blot分析证实，纯化的重组IL-18蛋白具有反应活性。上述研究结果为重组IL-18的应用奠定了基础。     

家蝇抗菌肽的研究进展马红霞

从家蝇抗菌肽的分类、结构特点、作用机理、诱变、活性检验以及分子生物学研究等方面介绍了家蝇抗菌肽的研究进展。家蝇抗菌肽独特的作用机理、成熟的诱导、分离纯化技术及其相关基因的克隆、表达等研究成果均为对家蝇抗菌肽进行更深入的研究奠定了基础。采用分子生物学技术有望筛选并制备大量的高效家蝇抗菌肽。     

天祝县草产业发展的制约因素及其对策

通过分析天祝县草产业发展现状，指出天祝县草产业发展存在的问题，提出要大力发展天祝县草产业必须加强天然草原综合改良，科学合理利用草原资源，建立人工草地和牧草种子繁育基地，开发草产品；建立多元化的投入机制，培植草产业开发的龙头企业；进一步完善草地管理制度，全面彻底地落实草原有偿承包责任制；建立信息网络体系，把信息网络纳入畜牧业基础设施建设范围内，建立健全草畜产品信息网络。     

猪白细胞介素-18基因表达及重组蛋白的纯化

以pcDNA3.1-IL18为模板进行PCR扩增获得猪白细胞介素-18(IL-18)的成熟肽基因,以KpnⅠ、SacⅠ双酶切PCR产物作为供体,KpnⅠ、SacⅠ双酶切的pET41c和pET32c作为载体,连接载体供体,转化DH5α,经双酶切、PCR鉴定及测序筛选出阳性重组质粒,并命名为pET41c-IL18和pET32c-IL18。将pET41c-IL18和pET32c-IL18转化大肠埃希氏菌BL21(DE3),用1 mmol/L IPTG 37℃诱导表达。SDS-PAGE及W estern-blotting分析结果表明,所表达的重组蛋白主要以包涵体形式存在,pET32c-IL18重组蛋白分子质量约33 ku,与预期大小相符。将包涵体提取物用8 mol/L脲变性,经N i-NTA柱纯化,透析复性,得到了纯化的IL-18蛋白。     

Biological characteristics of JAK2 transduced CD34+ cells from cord blood during ex vivo expansion

AIM: To explore the feasibility and biological characterization of long-term regulated expansion of JAK2 transduced human CD34⁺ cord blood cells in vitro.METHODS: A retrovirus (RV) vector which contains JAK2 catalytic domain and two binding sites for a chemical inducer,dimerization (AP20187),was cloned (designated MGI-F₂JAK2).CD34⁺cells were enriched from cord blood with a MiniMACS system.The purified CD34⁺ cells were transfected with supernatant from the retrovirus packaging cell line that expressed JAK2.Following transduction,cells were expanded into four groups: AP20187 alone,FL alone,TPO,alone,AP20187+FL+TPO,respectively.The expanded cells were monitored by GFP expression,immunophenotyping,progenitor colony assay,karyotype analysis as well as tumorigenesis in nude mice.RESULTS: The purity of selected CD34⁺ cells was over 91% and gene transfer rate was 49.32%±6.21%.Only the group of AP20187 +FL+ TPO was obtained a significant sustained outgrowth of the transduced CD34⁺ cord blood cells.The percentage of GFP+ cells consistently produced a rise to the 90% peak level by the end of 8th week of culture.Flow cytometry analysis showed that the phenotype of the expanded cells was CD33⁺,CD61⁺ and Gly-A⁺ partial positive;CD38⁺ and HLA-DR⁺ strong positive,while CD2,CD7 and CD19 were almost negative.Colony assays performed in methycelluos,which can give rise to BFU-E,CFU-GM and CFU-Mix,the CFU-GM was predominantly in all colonies.The tumor was not observed in nude mice and the karyotype analysis was normal from expanded cells.CONCLUSION: The results demonstrate that AP20187-mediated activation of JAK2 signaling is capable of stimulating expansion JAK2 transduced CB CD34⁺ cells in combination with FL and TPO.This system may have applications for studies in signaling transduction,hematopoiesis,and for gene and cell therapy.     

渠道渐变体土方计算的精确公式

渐变体作为衔接不同断面形式的过渡段,被广泛地用于输水建筑物工程中,但其土方计算目前没有统一科学的计算方法.为此,本文列出了工程中常见的几种渐变段形式,并通过对断面函数数学特性进行分析,得妹到了常见渐变体任一断面面积函教为二次抛物线.因此,可通过起始断面面积,终止断面面积和中断面面积唯一确定任一断面面积函数,并将该函数沿渐变体长度方向积分,推导出渐变段土方计算的精确、通用计算公式.计算实例表明计算过程简单、误差小,概念清晰,可供设计人员参考.