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。     

C18-磁性纳米颗粒萃取虾肉中氯霉素残留

建立了一种用C18键合磁珠固相萃取虾肉中氯霉素残留的方法。在Fe3O4超顺磁性纳米颗粒的表面键合C18基团,制备双功能反相萃取颗粒。用该颗粒对样品中的氯霉素残留进行固相萃取,对结合时间、温度、磁珠用量等因素进行了优化,建立磁珠法兽药残留固相萃取方法。用标准方法(SN/T 1864-2007)对萃取所得产物进行检测。经过优化,C18键合磁珠的最佳萃取条件为50℃结合5 min,用1 mL甲醇洗脱3次。检测结果显示该方法具有良好的精密度和回收率。在0.1～10μg/kg之间具有良好的线性关系,相关系数为0.9941,检出限为0.1μg/kg。该方法灵敏度高、重现性好、准确度高,可满足虾肉中氯霉素残留检测的需要。     

鸡白介素18基因原核表达质粒构建

根据已发表的江西土鸡白介素 -1 8(Ch IL-1 8) c DNA编码基因序列设计引物 ,用PCR技术从 p MDCh IL-1 8质粒扩增出编码鸡IL-1 8成熟蛋白基因 ,重组于 p BV2 2 0表达载体上 ,将重组质粒转化大肠杆菌 JM1 0 9(DE3 ) ,转化子经温度诱导的表达产物 ,SDS-PAGE电泳鉴定约 2万 ,N端开头 1 5个氨基酸序列测定分析 ,证明获得了鸡 IL-1 8成熟蛋白 ,为今后深入研究鸡 IL -1 8的生物学特性及其临床应用打下了基础     

PET/CT FOLLOWING INTENSITY-MODULATED RADIATION THERAPY FOR PRIMARY LUNG TUMOR IN A DOG

A primary lung tumor in a dog treated with intensity-modulated radiation therapy was imaged approximately 6 weeks and 1-year posttreatment with combined positron emission tomography (PET) and computed tomography, utilizing the radiotracers 18F-fluorodeoxyglucose and 18F-fluorothymidine. These two tracers allowed discrimination of tumor from inflammation, and demonstrated spread of tumor along airways over time after treatment. Fusion of functional imaging with anatomic imaging is a useful tool, particularly in the field of oncology, with the potential for PET markers that delineate tumor from normal or reactive tissue, and potential or actual response to therapy.     

山羊毛虱的形态结构和分子标志研究

为了解山羊毛虱形态结构和分子标志,用电子显微镜和三维立体显微镜观察了采自山羊的山羊毛虱形态结构,测定了其18SrDNA和cox1基因序列,并基于比对,揭示其序列特点。形态观察发现,触角3节,第1节短粗,第2、3节细长;中胸气门1对,位于前胸两侧;腹部有气门6对;跗节3节。序列分析显示,本样虱、山羊毛虱、具边毛虱和牛毛虱四者的18SrDNA基因序列高度相似,不适于做种间鉴定。cox1序列极不保守。     

Detection of molecular markers linked to the durable adult plant stripe rust resistance gene Yr18 in bread wheat (Triticum aestivum L.)

Stripe rust of wheat caused by Puccinia striiformis West. f. sp. tritici presents a serious problem for wheat production worldwide, and identification and deployment of resistance sources to it are key objectives for many wheat breeders. Here we report the detection of simple sequence repeat (SSR) markers linked to the durable adult plant resistance of cv. ‘Otane’, which has conferred this resistance since its release in New Zealand in 1984. A double haploid population from a cross between ‘Otane’ and the susceptible cv. Tiritea’ was visually assessed for adult plant infection types (IT) in the glasshouse and field, and for final disease severity in the field against stripe rust pathotype 106E139A⁺. At least three resistance loci controlled adult plant resistance to stripe rust in this population. Quantitative trait loci (QTL) mapping results revealed that two of these, one on chromosome 7DS corresponds to the durable adult plant resistance gene Yr18 and other on chromosome 5DL were contributed from ‘Otane’; while the remaining one on chromosome 7BL, was contributed from the susceptible ‘Tiritea’. Interval mapping placed the ‘Otane’‐resistant segment near the centromere of chromosome 7DS at a distance of 7 cM from the SSR marker gwm44. The stability of QTL in the two environments is discussed. SSR gwm44 is potentially a candidate marker for identifying the durable resistance gene Yr18 in breeding programmes.     

Exploring genetic diversity of rice cultivars for the presence of brown planthopper (BPH) resistance genes and development of SNP marker for Bph18

Brown planthopper (BPH) is the most devastating insect pest in rice‐growing areas. Information on availability of BPH resistance alleles and their sources enhances BPH‐resistant breeding programmes. In this study, 260 highly diversified rice cultivars or breeding lines were screened for the presence of five major BPH resistance genes (Bph10, Bph13, Bph18, Bph20 and Bph21) using gene‐specific markers. The analysis revealed that 137 of the 260 cultivars possess at least one BPH resistance gene. Bph10 was predominant while Bph20 was the least distributed. Moreover, two and three different resistance gene combinations were found in the cultivars. Molecular markers play an important role in molecular breeding programmes. A tightly linked PCR‐based co‐dominant Bph18 marker was developed, which is cost effective and time effective and simpler than available Bph18 CAPS marker (7312.T4A). We strongly believe that the identified BPH‐resistant cultivars can be used as alternative resistance gene sources and also as resource for novel BPH resistance genes. The developed Bph18 marker will be highly useful in molecular breeding applications of BPH‐resistant breeding programmes.     

陆地棉背景下海岛棉第18染色体片段置换系的培育及相关农艺性状QTL定位

Sub18是以陆地棉遗传标准系TM-1为背景, 含海岛棉3-79第18染色体的置换系材料。本研究以TM-1为受体亲本, 置换系Sub18为供体亲本, 借助分子标记辅助选择技术培育了一套以TM-1为背景, 含海岛棉3-79第18染色体不同长度片段的置换系。这套置换系由45个株系构成, 共78个置换片段。其中27个株系导入单片段, 占总株系的60%; 9个株系导入2个片段, 占20%; 9个株系导入3个及以上片段, 占20%。导入片段总长度为467.6 cM, 约为该染色体遗传长度的4倍, 每个株系内被替换的染色体片段长度不完全相同, 平均遗传长度为5.99 cM, 最短的为0.9 cM, 最长的20.35 cM。其中13个株系表现开放花蕾性状, 涉及的最短导入片段长5.05 cM。对TM-1、Sub18以及培育的45个导入系进行农艺性状调查和QTL联合定位分析, 鉴定出纤维强度(qFS-C18-1)、整齐度(qFU-C18-1)、马克隆值(qFMi-C18-1)、成熟度(qFMa-C18-1)、皮棉重(qLW-C18-1)、籽指 (qSI-C18-1)和衣分 (qLP-C18-1) 7个加性QTL和5个上位性效应QTL。研究结果为进一步精细定位目标QTL、克隆QTL以及重要性状分子设计育种奠定了基础。     

花生AhLEA18蛋白基因的克隆与表达分析

LEA蛋白家族是一类在种子胚胎发育晚期丰富表达的蛋白,在种子的正常发育过程中大量积累,同时在植物处于干旱、寒冷、盐胁迫等逆境条件下高水平表达,推测该类蛋白在缺水条件下具有一定的生理保护功能。根据蛋白序列特点,该蛋白家族分为多个组,LEA18蛋白属于其中一组蛋白。PvLEA18蛋白在干燥种子、花粉粒中大量积累,也参与到对水分缺失、ABA处理的生理应答过程过程。本研究从栽培种花生鲁花14中克隆得到一个LEA18基因,命名为AhLEA18。对其序列的生物信息学分析表明,AhLEA18具有典型LEA18蛋白序列特征。通过半定量RT-PCR的方法对该基因在花生植株不同组织及不同发育时期的种子中的表达情况进行了分析。     

Work-hardening Mechanism of Non-magnetic High Manganese ZG25Mn18Cr4 Castings

The important character of non-magnetic high manganese ZG25 Mn18Cr4 alloy is rapid work-hardening under external stress. With X-ray diffraction and TEM analysis, it is proved that the microstructures of both undeformed and deformed matrixes are austenite and carbide with some striation structure in the matrixes, the amount of stripes in the deformed matrix is obviously more than that in the undeformed matrix. Electronic diffraction analysis confirmed that the stripes in coarse austenite grains are high density lamination fault sheets. A great deal of lamination fault sheets produced by plastic deformation divides up austenite matrix, shortens the free distance of dislocation movement and results in the rapid work-hardening of ZG25Mn18Cr4 alloy.