红莲型水稻不育系与保持系线粒体DNA酶切分析

为研究红莲型水稻细胞质雄性不育的分子基础，我们提取纯化了红莲型水稻丛广４１Ａ和丛广４１Ｂ的线粒体ＤＮＡ，采用限制性内切酶酶切片段长度多态性（ＲＦＬＰ）方法比较了红莲型不育系和保持系线粒体ＤＮＡ酶切图谱，发现两者之间存在一定的差异，部分支持了细胞质雄性不育与线粒体ＤＮＡ有关的结论。     

水稻农虎26B保持系线粒体基因文库的构建

经Sau3AI部分酶解并脱磷的水稻农虎26B保持系的线粒体DNA与BamHI/EcoRI双酶切的λEMBL3AB载体DNA进行了连接,对连接物进行了体外包装,并感染NM538和Q359受体菌,得到了1.75×10~4个重组子.从中随机选取5个克隆的DNA,用BamHI进行酶切,琼脂糖凝胶电泳,出现了不同于载体DNA的酶切带型.另随机选取3个克隆的DNA,均与水稻线粒体DNA发生了杂交.由此认为,水稻农虎26B保持系线粒体基因文库确已建立.     

一种蛙病毒的纯化和酶切分析

从患病虎纹蛙（Rana tigrina rugulosa)蝌蚪中分离得到一种蛙病毒,感染鱼的FHM、CO、EPC细胞,获得大量的病毒原料,分离纯化得到高纯度的病毒粒子,电镜下可见病毒粒子为二十面体,具囊膜,直径平均为125nm。抽提病毒核酸,对其基因组DNA进行酶切分析,病毒基因组为双链DNA分子,表现脊椎动物虹彩病毒基因组的特点即其胞嘧啶5′端高度甲基化。以限制性内切酶XbaⅠ、BanHⅠ、HindⅢ、KpnⅠ和PstⅠ酶切病毒基因组DNA,经电泳分离后,分别得到13、25、6、14、22条清晰的酶切片段,并根据酶切片段算得基因组的大小超过100kb。用PCR方法,得到这个病毒的主衣壳蛋白（MCP）基因保守序列,与FV3相比,同源性达98％。     

草鱼线粒体DNA酶切图谱的研究

用１０种限制性内切酶对草鱼肝脏线粒体ＤＮＡ进行了分析，其分子太小约１６．５８ｋｂ．ＰｓｔＩ，ＢａｍＨＩ，ＸｂａＩ，ＢｇｌＩ，ＨｉｎｄⅢ，ＢⅡ，ＰｖｕⅡ，ＸｈｏⅠ，ＥｃｏＲⅠ，ＳａｌⅠ在草鱼ｍｔＤＮＡ分子上分别具有２，３，３，４，７，３，６，２，４及０个切点。根据单酶解及双酶解结果建立了草鱼ｍｔＤＮＡ的限制性酶切图谱。     

提取水稻线粒体DNA的一种简易方法

介绍了一种利用常用的普通试剂提取水稻线粒体DNA的简便方法 .与其它方法相比较 ,它具有省时、省钱、高效、快捷、简单等特点 .用该方法提取的水稻线粒体DNA ,经紫外分光光度计测定其纯度、限制性内切酶进行酶切和随机引物进行RAPD反应的结果表明 ,完全可以满足作为RFLP和RAPD等分析质量的要求 .     

大熊猫线粒体DNA酶切片段长度多态性研究

用１２种限制性内切酶（ＢａｍＨⅠ，ＥｃｏＲⅠ，ＥｃｏＲⅤ，ＸｈｏⅠ，ＰｓｔⅠ，ＭｓｐⅠ，ＸｂａⅠ，ＰｖｕⅡ，ＨｉｎｄⅢ，ＨａｅⅢ，ＳａｃⅠ，ＨｐａⅡ）对秦岭大熊猫线粒体ＤＮＡ进行了酶切。测定和分析了每种酶所产生片段的数量和大小，并与四川大熊猫的限制性片段进行了比较，发现在相同的６种酶的１６个酶切位点中有一个不同，表明这两地群体间存在着线粒体ＤＮＡ的多态性。其研究结果为进一步研究和保护大熊猫提供了重要依据。     

极端嗜热厌氧纤维素分解菌基因文库的构建及其内切葡聚糖酶基因片段的克隆

以从云南邦拿掌温泉中分离、纯化的高温厌氧纤维素分解菌邦2菌(Cadicellulosiruptor)为材料,制备其总DNA,经限制性核酸内切酶EcoRⅠ部分酶切后,在T4DNA连接酶的作用下与经EcoRⅠ完全酶切、去磷酸化的质粒载体pUC18连接,然后转化E.coliJM109,建立了邦2的基因文库,经筛选鉴定得到6.3×103个重组子;重组子经刚果红平板验证:约有23.5%菌落呈现透明圈;重组子经EcoRⅠ酶切验证显示:重组质粒均含有外源DNA插入片段.结果表明已克隆到邦2菌纤维素酶系中的内切葡聚糖酶基因(ED基因)片段.     

上海四膜虫(Tetrahymena shanghaiensis)线粒体DNA的酶切分析

该文以六种限制性内切酶对上海四膜虫ｍｔＤＮＡ进行单酶完全酶切,ＥｃｏＲⅠ、ＨｉｎｄⅢ、ＨｈａⅠ酶切均产生４个片段,ＰｓｔⅠ、ＨｐａⅡ、ＨａｅⅢ酶切分别产生５、６、７个片段。不同的酶切征段大小及总和有一定的差异,酶切结果比较,有较大的差异。同其它方法如四膜虫大核ｒＤＮＡ限制性内切酶分析、同工酶分析及皮层细胞骨架组分分析结果一致,进上步证明上海四膜虫是梨形四膜虫复合种的一种。     

绿头鸭mtDNA限制性内切酶酶切分析

采用碱变性法制备绿头鸭肝细胞ｍｔＤＮＡ，经纯化后测其分子量为１６．７ｋｂ．用限制性内切酶进行酶切分析，结果表明ＢａｍＨⅠ、ｐｓｔⅠ和ＨｉｎｄⅢ在绿卖鸭ｎｔＤＮＡ分子上分别有４个、２个和３个酶切位点。与由番鸭、北京鸭和建昌鸭肝细胞ｍｔＤＮＡ为材料所得的研究结果比较，发现绿头鸭与番鸭及家鸭在ｍｔＤＮＡ种质方面存在着高度差异。     

限制性酶切DNA片段的计算机辅助测量

文中对几种测量限制性内切酶解DNA片段大小方法的测量精度进行了比较。在所讨论的方法中有手工半对数作图法、线性回归、组合线性回归、拉格朗日插值法、Southern法及改进的分段函数法和其计算机计算程序。用以上方法检验了λDNA/HindⅢ+EcoRⅠ酶切片段的测量精度,并测量了pSaA基因限制性内切片段大小。结果表明改进的分段函数法给出最小标准方差(Sd)及最优测量一致性。     

Comparative genome research between maize and rice using genomicin situ hybridization

Using the genomic DNAs of maize and rice as probes respectively, the homology of maize and rice genomes was assessed by genomic in situ hybridization. When rice genomic DNAs were hybridized to maize, all chromosomes displayed many multiple discrete regions, while each rice chromosome delineated a single consecutive chromosomal region after they were hybridized with maize genomic DNAs. The results indicate that the genomes of maize and rice share high homology, and confirm the proposal that maize and rice are diverged from a common ancestor.     

分子标记鉴定红莲型细胞质雄性不育杂交水稻组合及其亲本

利用RAPD分子标记对红莲型细胞质雄性不育(HL—CMS)杂交水稻组合及其亲本进行了DNA多态性分析。从124个随机引物中筛选出具有非常明显的多态性，且只能扩增出1～5个片段的4个引物能有效地区分和鉴定红莲型(HL)2个杂交水稻组合(粤泰系列，从广系列)的杂种及其亲本。     

Optical mapping of a rice BAC clone using restriction endonuclease and imaging with fluorescent microscopy at single molecule level

A method of constructing restriction map by optical mapping and single molecule fluorescent microscopy is described. DNA molecules were aligned and adsorbed on a glass coverslip surface by a modified “molecular combing” technique, and then the surface-immobilized DNAs were cleaved in situ with a restriction endonuclease. Individual DNA molecules digested by the endonuclease EcoRⅠ were observable with fluorescent microscopy. Using optical mapping, a physical map of a rice bacterial artificial chromosome clone was constructed. This method will facilitate genomic mapping and tracing the dynamic process in real time at a single molecule level with fluorescence microscopy.     

不同作物间共用SSR引物的初步研究

根据相关报道,利用互联网在GENE BANK中查询油菜的简单重复序列及其两端序列来设计引物,并合成了2对甘蓝型油菜的SSR引物（Bn92A,Bn72A),通过所建立的降温PCR（Touchdown PCR)方法,对来自禾本科,十字花科,芸香科,锦葵科等12种经济作物的DNA进行PCR扩增。结果显示,PCR扩增产物条带清晰。所有12份材料用2对SSR引物扩增出的主带片段大小一致,分别为150bp(Bn92A),250bp(Bn72A）。这与文献报道在甘蓝型油菜中SSR扩增出的片段大小完全一致。本研究说明,各物种基因组间存在着相当大的相似性,这2对甘蓝型油菜的SSR引物可在其它经济作物分子标记的基因组比较作图应用。     

Selective coupling with K+ currents of muscarinic acetylcholine receptor subtypes in NG108-15 cells

The primary structures of two muscarinic acetylcholine receptor (mAChR) species, designated as mAChR I and mAChR II, have been elucidated by cloning and sequence analysis of DNAs complementary to the porcine cerebral and cardiac messenger RNAs, respectively. mAChR I and mAChR II expressed in Xenopus oocytes differ from each other both in acetylcholine-induced response and in antagonist binding properties. These results, together with the differential tissue location of the two mAChR mRNAs, have indicated that pharmacologically distinguishable subtypes of the mAChR represent distinct gene products. The primary structures of two additional mammalian mAChR species, designated as mAChR III and mAChR IV, have subsequently been deduced from the nucleotide sequences of the cloned cDNAs or genomic DNAs. We report here that mAChR I and mAChR III expressed in NG108-15 neuroblastoma-glioma hybrid cells, but not mAChR II and mAChR IV, efficiently mediate phosphoinositide hydrolysis, activation of a Ca2+-dependent K+ current and inhibition of the M-current, a voltage-dependent K+ current sensitive to muscarinic agonists.     

Stable replication of plasmids derived from Epstein-Barr virus in various mammalian cells

Epstein-Barr virus (EBV) infects human B lymphocytes, transforming the infected cells into dividing blasts that can proliferate indefinitely. The viral genome of 172 kilobase pairs (kbp) is a plasmid in most transformed cells. We have identified a region of EBV DNA, termed oriP (nucleotides 7,333-9,109 of strain B95-8), which acts in cis to permit linked DNAs to replicate as plasmids in cells containing EBV DNA. We have postulated the existence of a trans-acting gene allowing oriP function. Here we report that this gene lies in a 2.6-kbp region of the viral genome (nucleotides 107, 567-110, 176) which encodes the EBNA-1 antigen. We show that circular DNAs containing oriP, the EBNA-1 gene and a selectable marker replicate autonomously in cells derived from at least four developmental lineages and from at least three species. We also find that the one-third of the EBNA-1 gene repetitive in sequence is not essential for the trans-acting function that EBNA-1 gives oriP.     

Promoter of soybean early nodulin gene<Emphasis Type="Italic">enod2B</Emphasis> is induced by rhizobial Nod factors in transgenic rice

Nod factors, which are signaling molecules produced by Rhizobia, are the principal determinants of host specificity in Rhizobium-legume symbiosis. Nod factors can elicit a number of characteristic developmental responses in the roots of legumes, such as depolarization of the membrane potential in epidermal cells, specific expression of early nodulin genes and changes in the flux of calcium in root hairs, deformation of root hairs, cell division in the root cortex and formation of the nodule primordinm. Whether the rice plant can respond to signaling molecules (i.e. Nod factors) is an important question, as it could establish the potential for symbiotic nitrogen fixation in rice. The promoter of the soybean (Glycine max) early nodulin gene Gmenod2B fused to the β-glucuronidase (GUS) reporter gene was used as a molecular marker to explore whether Nod factors can be recognized by rice cells as signaling molecules. Transgenic rice plants harboring the chimeric gene Gmenod2BP-GUS were obtained via an Agrobacterium tumefaciens-mediated system. NodNGR factors produced by a broad-host-range Rhizobium strain NGR234(pA28) were used as probes to investigate the activity of the Gmenod2B promoter in rice. Our results showed that the early nodulin gene Gmenod2B promoter was induced by NodNGR factors in transgenic rice, and that it was specifically expressed in rice plant roots. Moreover, GUS gene expression driven by the Gmenod2B promoter in transgenic rice was regulated by nitrogen status. These findings indicated that rice possessed the ability to respond to Nod factor signals, and that this signal transduction system resulted in activation of the Gmenod2B promoter. Thus, we predict that the Nod-factor inducible nodulin expression system, which is similar to Rhizobium-legume symbiosis, may also exist in rice.     

抗稻瘟病和纹枯病的转基因水稻新品系

将水稻碱性几丁质酶基因（RC24）导入优良灿稻品种竹籼B,外源RC24基因可以稳定整合到RO代至R6代转基因水稻基因组中,并得到表达,已获得同时抗稻瘟病和纹枯病的转基因品系竹转68和竹转70以及43个转基因纯合株系。