革胡子鲶GH成熟肽在大肠杆菌中表达条件的优化

将携带革胡子鲶(Clarias lazera)生长激素(GH)成熟肽cDNA序列的重组表达载体pRSET-mGH转化入大肠杆菌Escherichia.coliBL21(DE3)pLysS中进行融合蛋白的表达。表达条件优化试验表明,表达菌株接种SOB培养基,培养2-3h后可用IPTG进行融合蛋白诱导表达;IPTG最佳诱导浓度为1.5 mmol/L,最佳诱导时间为4 h。本试验构建的原核表达体系为下一步革胡子鲶生长激素促生长制剂的研制奠定了基础。     

疏勒河中游土地利用与景观格局动态

利用1976年Landsat MSS、1989年Landsat TM、2000年Landsat ETM+和2010年TM遥感影像,运用GIS和景观生态学方法,分析了1976-2010年疏勒河中游玉门市土地利用/覆被和景观格局的变化.结果表明:1976-2010年间,玉门市土地利用类型转移的主要方向是草地和戈壁转化为耕地、耕地转化为建设用地、草地转化为戈壁;土地利用变化经历了“缓慢变化-急剧变化-显著变化”的过程,景观密度持续增大,最大斑块指数先增大后减小,面积加权形状指数增大,形状趋于不规则;斑块间的最邻近距离减小,景观逐渐向具有多种要素的密集格局演变,更加破碎;不同斑块间的分离度减小;景观的多样性和均匀度先减小后增加.农业人口增长和经济发展是研究区土地利用/覆被变化的最直接驱动力,气候和政策因素也是重要的影响因素.     

花香的生物合成、调控及基因工程研究进展

花香能提高观赏植物的审美特性,并且在植物的繁衍中起着重要作用。近年来,随着分子生物学的发展,花香分子水平的研究呈现加速发展的趋势,已成为当前的一大研究热点。该文主要论述了花香的生物合成途径及关键酶基因、分子水平的调控和共调控探索、花香基因工程策略,以期为花香性状改良提供参考。     

实生成年苹果树外植体的快速微型繁殖

试验结果表明:以实生成苹果树上的芽作为外植体,培养在添加1—2mg/l 6-BA的SH或MS培养基上,在继代培养时芽的萌发率达92％以上,50天内芽数增殖5—6.8倍;同期内,液体旋转培养比琼脂静置培养芽条长度要增加3倍左右;芽条在0.2—0.4mg/lIBA中生根率80％以上;试管苗的移栽成活率85％以上。     

动物细胞膜的分离纯化及其在病毒受体研究中的应用

细胞膜是动物细胞与胞外环境之间的屏障。病毒只有与细胞膜上的病毒受体特异性结合 ,才能进入细胞 ,进而启动其增殖周期。因此 ,病毒受体是病毒学研究的重要组成部分。分离纯化病毒受体所在的细胞膜作为病毒受体研究的实验材料 ,已经在许多病毒的研究中得到应用 ,并取得了很好的效果。现就动物细胞膜的分离纯化及其在病毒受体研究中的应用作一综述。     

再生稻二化螟幼虫空间分布型和抽样技术的研究

再生稻二化螟幼虫的空间布型为负二项分布和聚集分布,其lwao的线性回归方程为m^*=0.0099 2.4753m,属负二项分布。根据聚集均数（λ）测定结果,分析了聚集原因,在分布型研究的基础上,探讨了资料代换模式,Kuno‘s种群序贯抽样模型和最适抽样数模型。     

中国河南两株庚型肝炎病毒（HGV）NS5区部分cDNA的克隆与序列分析

通过逆转录－聚合酶链反应从我国河南省２例重叠感染ＨＣＶ或ＨＢＶ／ＨＤＶ的献血啼中,分离到ＨＢＶＮＳ５区的部分ｃＤＮＡ,对其进行序列分析比较,结果表明,河南株ＨＧＶＮＳ５工核苷酸与两中国ＨＧＶ主同源性高于国外代表株（８８．５－９０．６％）,但由核苷酸推导的氨基酸的同源性都无明显的地区性区别。ＨＧＶＮＳ５区氨基酸序列较保守,缺乏明显高变区,中国４株ＨＧＶ在７３８４位发生了由Ｃ→Ｔ的变异,从而导致一个人     

生态因子的波动对多刺裸腹溲雄体发生的影响

采用克隆培养法,研究了几种主要生态因子的波动对多刺裸腹溲雄体发生的影响和该溲对上述生态因子波动的敏感程度。结果表明,无论是一次性剧烈刺激,还是持续性渐进刺激,该溲均未能直接产生雄体,即溲的孤雌生殖雌体不能直接转变为混交雌体（两性生殖雌体）;在光照、温度、饵料密度、ｐＨ值持续性渐进波动时,该溲种群的内禀增长率分别为０．７７４８、０．７４８１、０．６５３９和０．６３１０ｄ＾－１ｉｎｄ＾－１,比对照组降     

miR-22 regulates C2C12 myoblast proliferation and differentiation by targeting TGFBR1

Recently, miR-22 was found to be differentially expressed in different skeletal muscle growth period, indicated that it might have function in skeletal muscle myogenesis. In this study, we found that the expression of miR-22 was the most in skeletal muscle and was gradually up-regulated during mouse myoblast cell (C2C12 myoblast cell line) differentiation. Overexpression of miR-22 repressed C2C12 myoblast proliferation and promoted myoblast differentiation into myotubes, whereas inhibition of miR-22 showed the opposite results. During myogenesis, we predicted and verified transforming growth factor beta receptor 1 (TGFBR1), a key receptor of the TGF-β/Smad signaling pathway, was a target gene of miR-22. Then, we found miR-22 could regulate the expression of TGFBR1 and down-regulate the Smad3 signaling pathway. Knockdown of TGFBR1 by siRNA suppressed the proliferation of C2C12 cells but induced its differentiation. Conversely, overexpression of TGFBR1 significantly promoted proliferation but inhibited differentiation of the myoblast. Additionally, when C2C12 cells were treated with different concentrations of transforming growth factor beta 1 (TGF-β1), the level of miR-22 in C2C12 cells was reduced. The TGFBR1 protein level was significantly elevated in C2C12 cells treated with TGF-β1. Moreover, miR-22 was able to inhibit TGF-β1-induced TGFBR1 expression in C2C12 cells. Altogether, we demonstrated that TGF-β1 inhibited miR-22 expression in C2C12 cells and miR-22 regulated C2C12 cell myogenesis by targeting TGFBR1.     

Identification and genetic mapping of four novel genes that regulate leaf development in Arabidopsis

Molecular and genetic characterizations of mutants have led to a better understanding of many developmental processes in the model system Arabidopsis thaliana.However,the leaf development that is specific to plants has been little studies.With the aim of contributing to the genetic dissection of leaf development,we have performed a large-scare screening for mutants with abnormal leaves.Among a great number of leaf mutants we have generated by T-DNA and transposon tagging and ethylmethae sulfonate (EMS) mutagenesis,four independent mutant lines have been identified and studied genetically.Phenotypes of these mutant lines represent the defects of four novel muclear genes designated LL1(LOTUS LEAF 1),LL2(LOTUS LEAF2),URO(UPRIGHT ROSETTE),and EIL(ENVIRONMENT CONDITION INDUCED LESION).The phenotypic analysis indicates that these genes play important roles during leaf development.For the further genetic analysis of these genes and the map-based cloning of LL1 and LL2,we have mapped these genes to chromosome regions with an efficient and rapid mapping method.