生物合成谷胱甘肽种间耦合ATP再生系统的构建

利用重组大肠杆菌Ⅱ 1中的谷胱甘肽合成酶系和面包酵母WSH J7中的ATP生物合成酶系 ,构建了一个以葡萄糖为能源的种间耦合ATP再生系统。经过通透性处理的酵母细胞几乎不能消耗葡萄糖。在反应体系中添加 1mmol/LAMP和 0 0 5mmol/LNADH ,即可启动酵母的酵解途径。提高耦合系统中的葡萄糖浓度 ,可促进GSH的合成。当葡萄糖浓度为 40 0mmol/L时 ,系统内GSH浓度达到 1 0 4mmol/L(3 2 g/L)。Mg2 +缺乏时 ,耦合系统和外加ATP的非耦合系统均不能合成谷胱甘肽。耦合系统中Mg2 +与ATP形成螯合物 ,可能是导致耦合系统中GSH产量较低的原因。在耦合系统中补加Mg2 +,反应 6h时GSH浓度达到 1 4 3mmol/L(4 4g/L)。     

陈旧皮张中DNA提取的新方法

对传统的馆藏陈旧皮张标本DNA提取方法进行了改进,所提DNA分子量可达1kb,而且具有样品用量少（约0.01g),消化时间短（约14h)和操作步骤简单等优点,利用所提DNA,对小熊猫等珍稀动物线粒体DNA的细胞色素b和控制区序列的部分片段进行了PCR扩增,序列测定和比较分析,证实所提DNA合格而无污染,完全可以用于珍稀动物保护遗传学研究。     

满江红鱼腥藻遗传多样性的RAPD分析

共生在水生蕨类植物满江红(又称“红萍”:Azolla)叶腔中的固氮兰细菌曾被认为是一个种满江红鱼腥藻(Anabaena azollae Strasb.).但由于现存的满江红在分类学上有2个亚属,7个种1,对不同满江红叶腔中鱼腥藻的鉴别,多年来引起人们的重视.80年代,鱼腥藻的单克隆抗体和RFLP的研究,发现了它与宿主分类上一定程度的对应关系2,3.90年代以后,Van Coppenolle和Eskew分别以RAPD-PCR和DAF-PCR对从满江红共生体中提取的DNA进行了分析4,5,但后者发现了共生体中藻的DNA对整个PCR产物的干扰作用会影响满江红属本身系统分类.       

中国人群中微卫星位点DXYS156的多态研究

以中国２个汉族群体和８个少数民族群体的Ｓ２０名个体为研究,采用ＰＣＲ扩增后案丙烯酰胺凝胶电泳分离的方法,分析了Ｙ染色体上ＤＸＹＳ１５６Ｙ和Ｘ染色体上ＸＹＳ１５６Ｘ这两个微卫星位点的遗传多态性。结果表明,在所研究的１０个中国人群中,共观察到１０个不同长度片段的等位基因,在Ｘ染色体上的５个闰基因是：１３０ｂｐ、１３５ｂｐ、１４０ｂｐ、１４５ｂｐ、１５０ｂｐ,在Ｙ染色体上的五个等位基因晃：１６０ｂｐ、１     

02428×合系35 RILs群体糙米和发芽糙米γ-氨基丁酸、抗性淀粉的遗传分析

以水稻02428×合系35的RILs群体及其亲本糙米和发芽糙米为材料,对糙米、发芽糙米各222个群体样品的γ-氨基丁酸、抗性淀粉含量进行测定,以期选育出高γ-氨基丁酸、高抗性淀粉的水稻新品种。研究结果表明,重组自交系糙米、发芽糙米γ-氨基丁酸含量差异不大,群体间存在广泛变异,由主效基因控制。重组自交系糙米、发芽糙米抗性淀粉含量差异大,发芽糙米抗性淀粉平均含量是该群体糙米的1.2倍,群体间存在广泛变异,呈偏态分布。高海拔冷凉气候有利于糙米高抗性淀粉含量的提升与进化。本研究可以为功能水稻的遗传及品种选育提供一定的理论依据。     

微流控芯片电泳及其法医学应用

在光学性能良好的Brofloat玻璃电泳芯片上,利用自行搭建的共聚焦激光诱导荧光检测系统,通过对芯片管道表面修饰、筛分介质、分离电场强度、进样方式、电泳温度、进样时间等条件的优化,对含15个STR基因座的法医DNA样品进行电泳分离测试实验.通过对芯片电泳条件优化获得了本电泳系统的最佳条件,成功实现8 min内完成DNA样品片段的分离,表明该微流控芯片电泳系统在法医DNA快速分析方面具有良好的应用前景.     

Genealogy and phylogeography of Cyprinid fish Labeo rohita （Hamilton, 1822） inferred from ATPase 6 and 8 mitochondrial DNA gene analysis

ATPase 6/8 gene （842 bp） of mitochondrial DNA was sequenced in Labeo rohita samples （n = 253） collected from nine rivers belonging to four river basins; Indus, Ganges, Brahmaputra and Mahanadi. Analysis revealed 44 haplotypes with high haplotype diversity （Hd） 0.694 and low nucleotide diversity （π） 0.001. The within population variation was larger （83.44%） than among population differences （16.56%）. The mean Fsv value （0.166; P 〈 0.05） for overall populations revealed moderate level of genetic structuring in the wild L. rohita populations. The haplotype network presented a single clade for wild L. rohita population, from different rivers. Negative values for Fu＇s index （Fs）, mismatch distribution analysis indicated period of expansion in L. rohita population. The time after recent expansion was estimated for each population, between 0.042 to 0.167 mya. The pattern of Isolation by Distance （IBD） was not significant （r = -0.113, P 〈 0.287）, when all the sampling locations were compared （Mantel test）, however, when an outlier （Indus, Brahmaputra and Mahanadi） was removed from the whole population set, a clear positive correlation between pairwise Fsv and geographic distance （Km） was seen. The analysis of data demonstrated that ATPase6/8 gene polymorphism is a potential marker to understand genetic population structure of wild L. rohita existing in different rivers. The study identified population substructure in wild L. rohita with common ancestral origin [Current Zoology 60 （4）： 460--471, 2014].     

美国高级联邦生物技术机构的调整

据美国微生物学会会讯(ASM News)1990年12期载文介绍,最近美国对监管生物技术的几个高级委员会进行了调整。布什总统科技政策办公室(OSTP)的官员宣布:由生物技术研究分委员会(BRS)取代存在了五年的生物技术科学协调委员会(BSCC)。     

PIK-75 promotes homology-directed DNA repair

Homo!ogy-directed repair(HDR)is one of two major DNA repair pathways to mend the double-strand breaks(DSBs)formed in the genome(Liang et al.,1998;Pardo et al.,2009).Although less efficient compared with another DNA repair pathway,nonhomologous end joining(NHEJ),HDR is a type of precise repair to restore DNA damage and sustain genomic stability(Pardo et al.,2009;Ceccaldi et al.,2016).By contrast,NHEJ usually introduces mutations into the repaired site,thus probably harming the genomic integrity(Lieber et al.,2003).The error-free property enables HDR to be harnessed to correct a faulty mutation for therapeutic purpose in cells or in the body(Wu et al.,2013).In add让ion,HDR possesses great potential in the generation of genome-edited animals with precise genetic modifications,such as point mutation,DNA replacement,and DNA insertion in a specific genomic site(Wang et al.,2013).However,the low repair frequency mediated by HDR significantly limits让s application for efficient gene correction or establishment of various genetically modified animal models.Currently,multiple site-specific endonucleases have emerged as highly efficient tools to create targeted DSBs and markedly promote subsequent DNA repair either via HDR or NHEJ(Gaj et al.,2013).Nonetheless,the HDR-mediated modifications following the cleavage of engineering nucleases are still inefficient,usually with an efficiency less than 20%in cultured mammalian cells and embryos(Mali et al..2013;Wang et al.,2013;Yang et al.,2013).