Fine mapping of the red plant gene R1 in upland cotton(Gossypium hirsutum)

Sub 16 is a substitution line with G. hirsutum cv. TM-1 genetic background except that the 16th chromosome (Chr. 16) is replaced by the corresponding homozygous chromosome of G. barbadense cv. 3-79, and T586 is a G. hirsutum multiple gene marker line with 8 dominant mutation genes. The R ₁ gene for anthocyanin pigmentation was tagged in Chr. 16 in T586. The objective of this research was to screen SSR markers tightly linked with R ₁ by using the F₂ segregating population containing 1259 plants derived from the cross of Sub 16 and T586 and the backbone genetic linkage map from G. hirsutum×G. barbadense BC₁ newly updated by our laboratory. Genetic analysis suggested that the segregation ratio of red plants in the F₂ population fit Mendelian 1:2:1 inheritance, confirming that the red plant trait was controlled by an incomplete dominance gene. Preliminary mapping of R ₁ was conducted using 237 randomLy selected F₂ individuals and JoinMap v3.0 software. Then, a fine map of R1 was constructed using the F₂ segregating population containing 1259 plants, and R ₁ was located between NAU4956 and NAU6752, with only 0.49 cM to the nearest maker loci (NAU6752). These results provided a foundation for map-based cloning of R ₁ and further development of cotton cultivars with red fibers by transgenic technology. Supported by National Natural Science Foundation of China (Grant No. 30730067) and Programme of Introducing Talents of Discipline to Universities (Grant No. B08025)     

Generation of transgenic cucumbers with expression of a ten-tandem repeat long-acting GLP-1 analogue and their biological function on diabetic rats

Glucagon-like peptide-1 （GLP-1） is a 30-amino acid peptide hormone, which has the regulatory function of stimulating the secretion of insulin to balance blood glucose levels. In this study, marker-free expression vector pX6 with a fusion gene of ten tandem repeated GLP-1 analog （[Ser8, Gln26 and Asp34]-GLP-1） genes was constructed and transformed into cucumbers by Agrobacterium tumefaciens-mediated transformation method. Four transgenic lines were obtained by PCR and Southern blotting analysis and two transgenic lines successfully expressed the fusion protein （named GLP-T）, which was revealed by Western blotting analysis. The biological activity test results showed that the serum glucose level of diabetic rats was significantly decreased after oral administration of the fusion protein GLP-T extracted from the transgenic cucumber fruitage. These results suggest that this may provide a brand-new strategy to prevent and cure the diabetes with no pain.     

小麦染色体配对基因Ph1结构剖析及调控机制研究进展

近年来,关于小麦抑制部分同源染色体配对基因Ph1的研究有了突破性进展.本文对该基因的结构和调控机理的最新研究进行综述.通过创造和分子标记鉴定Ph1缺失突变体,利用分子生物学及比较基因组学技术,该基因位点被界定于5BL上一个2.5 Mb的区域内,含有一个类cdk基因簇,且在该类cdk基因簇中插入一个亚端粒异染色质片段.细胞学研究显示,Ph1基因通过控制亚端粒的互作启始染色体识别和配对伙伴选择.与此同时,生物信息学揭示,这些类cdk基因与人类和老鼠的cdk2基因高度同源,它们与细胞周期中DNA复制、染色质凝集、碱基错配修复等事件相关.减数分裂时,该基因位点通过"感知"染色体的同源性程度而触发染色质的构象变化,从而控制染色体的配对和重组.此外,小麦中可能存在一种与Ph1相关的类似于酵母中的粗线期检查点机制.预测未来的研究将可能集中在Ph1对染色体同源性的"感知"机制、Ph1的开启与关闭、植物减数分裂重组的忠实性及减数分裂过程的检查点机制等方面.     

凋亡基因Survivin在宫颈鳞癌中的表达及其相关性

目的:探讨不同分期宫颈鳞癌组织中Survivin基因表达的特征及其临床意义.方法:应用免疫组化法(S-P法)及图像分析技术检测凋亡基因Survivin在38例宫颈鳞癌的表达情况.0期9例、Ⅰ b期10例、Ⅱa期7例、Ⅱb期7例、Ⅲa期5例,将0期及Ⅰ b期合并为早期,Ⅱa期～Ⅲa期合并为晚期.结果:在早期和晚期宫颈鳞癌组织中均有凋亡基因Survivin的阳性表达,但表达强度不同,早期宫颈鳞癌组织中Survivin PU值为(20.65±4.57),而晚期宫颈鳞癌组织中Survivin PU值为(24.94±5.64),两者比较有统计学差异(P<0.05).结论:Survivin基因在宫颈鳞癌组织中异常表达与宫颈鳞癌的发生及临床分期相关.     

秀丽小杆线虫Caenorhabditis elegans pkc-2基因cDNA的克隆和表达

蛋白激酶C在秀丽小杆线虫中具有调节肌细胞渐进性萎缩的功能.为了揭示它的调节机制, 本研究克隆了秀丽小杆线虫中蛋白激酶C pkc-2基因的cDNA pkc-2-c,构建了含该pkc-2基因cDNA亚型的重组质粒pPD 118.20-pKG 63;揭示了该cDNA在秀丽小杆线虫体壁肌细胞中的定位.     

丝状真菌米曲霉外源基因表达系统的构建

以米曲霉Aspergillus oryzae RIB40的基因组DNA为模板,PCR扩增得到启动子、终止子、筛选标记基因等表达元件,依次连接到载体pUC119上,构建了米曲霉的重组表达载体pNMA. 将米赫根毛霉脂肪酶基因(RML)连接于pNMA的启动子下,得到表达载体pNMA-RML,通过ApaI酶切线性化转化米曲霉宿主菌A.oryzae niaD300,得到整合型的阳性转化子A.oryzae ONL1. 其培养7天的培养液上清在以三丁酸甘油酯为底物的平板上形成清晰的水解透明圈,碱滴定法酶活测定表明培养液酶活可达2.5 U/mL,培养液上清的SDS-PAGE图谱在32.5 kDa处有RML的特征条带. 以上结果表明RML已经在米曲霉中成功表达,同时证明所构建的米曲霉外源基因表达系统是有效的.     

H0.8Ni0.4Ti1.6O4/TiO2纳米复合材料的合成及光催化性质

用固相合成法制备出K0.8Ni0.4Ti1.6O4,并用离子交换法制备出H0.8Ni0.4Ti1.6O4;通过C6H13NH2层间膨胀,TiO2粒子的插入和紫外光分解等反应,合成出一种新的层状光催化纳米复合材料H0.8Ni0.4Ti1.6O4/TiO2.X射线衍射和漫反射等表征结果表明:该样品的层间高度为0.37 nm,禁带能隙为3.35 eV和2.58 eV.用可见光范围(大于400 nm)的光照射30 min,0.4 g样品可使甲基橙溶液(20 mg/L)的降解率达到21.9%,而同样条件下,标准TiO2(P-25)仅为6.2%,表明所研制的层状纳米复合材料具有较高的光催化活性.     

一类不确定线性时滞系统的H∞控制

基于稳定性理论,利用Lyapunov泛函和线性矩阵不等式处理方法,结合自由权矩阵思想,研究了一类多个范数有界不确定的线性时滞系统的H∞控制问题,给出系统具有H∞性能的一个线性矩阵不等式条件．所设计的控制器对于系统所允许的参数不确定性和时滞,能保证闭环系统渐近稳定且具有理想的性能指标．     

根癌农杆菌介导的GFP在洋葱表皮细胞定位研究

采用根癌农杆菌介导的方法,以受控于CaMV35S启动子的携带有GFP报告基因的双元植物表达载体pCAMBIA1300-35S-GFP转化洋葱表皮细胞.荧光显微镜下观察结果显示,GFP基因在经浸染和共培养后的洋葱表皮细胞中得到了表达,绿色荧光分布在细胞核和细胞质中,为进一步研究新基因的亚细胞定位和瞬时表达奠定了基础.     

乙酰氨基丙二酸二乙酯的量热学研究

用精密自动绝热量热仪测定了乙酰氨基丙二酸二乙酯在78—395K温区的摩尔热容．根据实验测定的热容数据,用最小二乘法拟合计算出热容对温度的多项式方程,得到其相变焓、相变熵分别为34．295kJ·mol^-1、93．009J·K^-1·mol^-1．根据热力学函数关系式计算了其在80—395K温区每隔5K的热力学函数[HT—H298．15]和[ST-S298.15]．此外,用TG—DSC热分析技术进一步考查了该物质在相变区间的重复性和可靠性．