杉木单染色体扩增产物的RAPD分析

在显微操作器上微分离杉木(Cunninghamia lanceolata(Lamb.)Hook)的4条单染色体，以简并寡核苷酸为引物进行PCR扩增(DOP—PCR)，并将其DOP—PCR产物进行RAPD分析。结果表明，不同染色体扩增产物间有明显多态性；用RAPD-PCR的方式可反应出不同染色体遗传信息的差异，从这些差异中可能找到属于某单染色体的特异信息，进而在分子水平上对染色体进行编号。     

黑麦B染色体显微切割和微克隆

显微分离出两条黑麦Ｂ染色体,经蛋白酶Ｋ处理,Ｓａｕ３ＡＩ酶切后,用ＬＡ－ＰＣＲ（ＬｉｎｋｅｒＡｄａｐｔｅｒＰＣＲ）方法进行扩增,得到０．２～２ｋｂ的ＤＮＡ片段．Ｓｏｕｔｈｅｒｎ杂交分析结果表明,此扩增产物来源于黑麦Ｂ染色体．将部分ＰＣＲ产物克隆到ｐＵＣ１９载体中,获得了５０００个克隆．为构建Ｂ染色体ＤＮＡ文库奠定了基础     

固定标本的DNA提取及PCR扩增

报道富尔马林、酒精固定的日本绒螯蟹标本的ＤＮＡ提取及ＰＣＲ扩增，并与冷冻、煮沸标本进行了比较。结果表明，福尔马林固定标本与酒精固定标本一样可以撮加入的蛋白酶Ｋ量越多，ＤＮＡ的回收率越高。以提取的ＤＮＡ为模板，进行了线粒体ＤＮＡ１２ＳrＲＮＡ和Ｄ－１ooＰ基因片段的ＰＣＲ扩增，经琼脂糖产电泳ＰＣＲ扩增产物后均得到了与期待的碱基长度相一致的清晰谱带。     

水稻染色体微切割及4号染色体酶解片段的扩增

通过细胞分裂的同步化,低渗,酶消化,瞬间固定和涂片等制片技术,快速制备水稻根尖体细胞染色体标本。该方法制备出的染色体标本,杂质少,染色体分散程度好,满足了染色体微切割用片的要求。染色体微切割和ＰＣＲ扩增技术,获得了水稻第４号染色体ＤＮＡ文库。     

水稻染色体的显微分离与克隆

对水稻染色体识别、显微分离与切割、PCR体外扩增和微克隆进行了研究 .利用改进的显微切割装置 ,可以在 1 0 0×油镜下进行染色体分离与微切割 ,不仅解决了水稻染色体的识别和显微分离的困难 ,而且可使染色体特定区微切片段缩小到 7Mb级 ;利用 SUP-PCR可使 fg级水稻染色体 DNA扩增到 μg级 .电泳检测结果表明 ,扩增片断在 80～ 60 0 bp左右 ,经与 p UC1 9连接 ,转化大肠杆菌 DH5a,一次分离的单条水稻染色体可以获得 9×1 0 4克隆 ,一个 7Mb级片段可以获得 3× 1 0 4克隆 ,经分析 ,插入片段大小在 80～ 50 0 bp范围 .该方法为直接从水稻单条染色体或染色体特定区 DNA文库中筛选分子标记奠定了基础 .     

无胶毛细管电泳分离碱基对范围宽的DNA片段

提出一种无胶毛细管电泳分离碱基对范围宽的ＤＮＡ片段的方法。用ＤＢ－１气相色谱毛细管柱，以羟乙基纤维素为筛分介质，研究了λＤＮＡ－ＥｃｏＲⅠ＋ＨｉｎｄⅢ限制性片段的分离，分离效率达１．２×１０＾６板／ｍ，检测限为２．１×１０＾－１７ｍｏｌ。应用于一种鲤鱼种族鉴别基因的聚合酶链反应扩增产物的分离鉴定，结果与实际相符，分离速度比传统电泳方法提高２０倍。     

提高黄鳝减数分裂粗线期染色体分散程度

以黄鳝精巢为材料，采用药物处理提高黄鳝染当色体分散程度。结果表明：在低渗时，分别用８－羟基喹啉，α－溴萘和对二氯苯三种化学药物进行预处理５小时，同时结合用加氯仿和固定剂进行固定、高滴片等方法，可以使黄鳝减数分裂期染色体适当缩短，获得较好的染色体分散效果。     

葎草单染色体的显微分离及DOP-PCR技术体系建立

葎草是具有XX/XY1Y2性染色体系统的雌雄异株植物,是研究植物性染色体演化的模式材料之一.利用染色体显微分离技术从葎草根尖有丝分裂中期分裂相中将单条染色体进行了显微分离及DOP-PCR(Degenerate oligonucleotide primer-PCR)扩增,并构建了单染色体DOP-PCR扩增产物的荧光探针,对葎草根尖有丝分裂中期分裂相染色体进行了荧光原位杂交,其结果表明荧光信号分布在所有的染色体上,表明所建立的技术体系能够成功分离葎草单染色体并进行DNA扩增.本研究结果为进一步进行葎草X,Y染色体的细胞及分子生物学研究提供了技术支持.     

蓖麻蚕性细胞发育过程染色体的银染观察

用银染法观察了蓖麻蚕生殖细胞的染色体。结果表明：有丝分裂中期染色体上无特异的ＮＯＲｓ；精母细胞减数分裂偶线期和粗线期核仁逐步弥散，粗线期之后有一个染色体分散为染色质，核仁弥散于其中形成嗜银的二价体的第二收缩期和混乱期；卵母细胞的相应时期，有一个核仁扩增的过程。依据染色体嗜银性的强弱，探讨了前期Ⅰ，中期Ⅰ以及有丝分裂中期染色体的ｒＤＮＡ转录活性。     

石蒜凝集素基因的克隆

用石蒜科植物凝集素基因的保守序列为引物，利用RACE－PCR技术从石蒜幼嫩叶片中克隆出石蒜凝集素的全长cDNA，通过比较石蒜同其他石蒜科植物凝集素基因序列和推测的氨基酸序列，发现石蒜凝集素基因编码一具有信号肽的前体蛋白，石蒜凝集素同其他石蒜科植物凝集素一样为具有3个甘露糖专一结合盒的凝集素。     

Construction of single-chromosome DNA library fromLilium regale Wilson

A protocol of simple rapid microdissection of single-chromosome, amplification and cloning of its DNA fromLilium regale Wilson is described. Single-chromosome, microdissected by micromanipulator, was put into a 0.5 mL Eppendorf tube and digested with Sau3A, and then the Sau3A linker adaptors were ligated to the ends of DNA fragments. After 2 rounds of PCR amplification with one chain of linker adaptor as primer, the PCR products thus obtained have a length of 300–2500 base pairs (bp) with predominant fragments at about 1000 bp. Southern blot analysis confirmed that the PCR products originated from the genome ofLilium regale Wilson. By cloning the amplification products from the second round of PCR, single-chromosome DNA library was constructed, in which about as many as 100000 recombinant clones were produced. A total number of 84 clones were analysed, and it was revealed that the inserts ranged in size from 300 to 1800 bp, with an average of780 bp. Compared with the methods described in other literature, this protocol, eliminating the need for enzymatic digestion and ligating micromanipulation of chromosomal DNA in nanoliter volumes, permits the efficient amplification of single chromosome (not tens of chromosomes as reported before) and the fragments (780 bp in average) cloned in this study are longer than those reported before (650 bp in average).     

豌豆豆球蛋白（leguminA）基因的PCR扩增与鉴定

豆类的贮存蛋白是人类的植物蛋白主要来源之一,稻米平均蛋白质含量只有8％,而且人类必需的赖氨酸含量较少。如果将较富赖氨酸的豆类贮存蛋白基因转移到水稻中,提高稻米的蛋白质和赖氨酸等氨基酸的含量,是改善米质的重要途径之一。 Sun首先从法国菜豆中分离出菜豆贮存蛋白基因(Gl),随后,Lycett分析了豌豆主要     

Chromosome microdissection by laser microbeam, chromosomal fragment isolation and amplificationin vitro in barley (Hordeum vulgare L.)

A method for microdissection, isolation and amplification of plant chromosomal fragments using laser microbeam and a glass microneedle was established. Firstly, 7H chromosome of barley (Hordeum vulgare L.) was dissected by Nd: YAG laserbeam with suitable parameters and the fragment comprising a satellite was isolated with a glass microneedle which was fixed on a micromanipulator. Then, the chromosomal fragment DNA was amplified by LA_PCR (linker adaptor PCR) for two rounds. The size of the DNA fragments of PCR products varied from 500-3 000 bp and the PCR products originated from the genome of barley were verified by Southern hybridization. Compared with previous reports, there are some advantages in this research. The performance is easier, the dissection is more precise and the cost is low. It also permits efficient amplification with only one single chromosome fragment. Laser microbeam_glass microneedle method may be useful in the microdissection of special chromosome regions, especially in plants with middle or small chromosomes.     

安徽省九华山野生石蒜居群的核型研究

以安徽境内九华山野生石蒜根尖细胞为材料,报道了野生石蒜的染色体数目并对核型进行了分析.结果表明:九华山野生石蒜染色体的数目为2n=22,有3对亚端部着丝点区染色体,8对端部着丝点区染色体,按照Levan(1964)等标准,其核型公式为2n=6st 16t,未见随体.它的染色体长度比为1.84,属于Stebbins(1971)的"4A"核型;九华山野生石蒜染色体的形态为长椭圆形,与以前的报道有所差异,在石蒜种中迄今未见报道.     

Studies inin situ PCR detected by the BrdU antibody technique

Using the BrdU antibody technique followed by an immuno-chemical staining (BAT), the amplification of DNA fragments specific to human Y chromosome on cell specimen slides was efficiently detected. Whether direct BrdU incorporation into PCR products orin situ hybridization with PCR products on slides, the amplified target DNA fragments of specimen were visualized by BAT under the microscope. The availability of BAT and differences in the sensitivity and efficiency between BAT and dig-11-dUTP labeling in cellin situ PCR were discussed. Zhang Xiyuan: born in Oct. 1935, Professor, Current research interest in Cellular and Molecular Biology Supported by the National Natural Science Foundation of China     

半随机单引物PCR扩增产物的特异性研究

以Ｍ１３ｍｐ１９为模板,寡核苷酸“１２２４”为引物,进行半随机单引物ＰＣＲ扩增;分析其扩增产物的限制性内切酶酶切图谱,推定它们分别在Ｍ１３ｍｐ１９序列中的确切位置;证实引物“１２２４”的３端与模板Ｍ１３ｍｐ１９负链的互补结合,至少需有连续的４上个核苷酸,才能产生单引物ＰＣＲ扩增的模板分子,进行有效的ＰＣＲ扩增,并由此决定了扩增产物中各ＤＮＡ片段的大小及其在模板ＤＮＡ序列中的特定位置。     

瑞氏木霉内切-β-1,4葡聚糖酶基因Egl1的分子改造

为了提高瑞氏木霉(Trichoderma reesei)的纤维素酶活力,用分子改造的方法改造其内切-β-1,4葡聚糖酶基因Egl 1.用DNase I消化EglL 1,回收50～200bp的片段,用T4 DNA连接酶连接回收的片段,进行PCR反应,将PCR产物转入瑞氏木霉原生质体,用比较滤纸酶活力的方法筛选纤维素酶活力...     

三索线蛇与过树容蛇肝线粒体DNA的纯化与限制酶图谱

用Sepharose 4B凝胶柱过滤和NaCl离心法纯化了三索线蛇及过树容蛇肝线粒体DNA(mtDNA),它们的分子长度分别为17.75kb及19.70kb。分别用EcoRⅠ,XbaⅠ,BamHⅠ及BglⅡ等4种限制酶消化这两种mtDNA,结果表明:EcoRⅠ,XbaⅠ,BamHⅠ和BglⅡ在三索线蛇肝mtDNA上分别有1,1,2及3个切点;在过树容蛇肝mtDNA上各有4,1,1和2个切点。根据mtDNA的单酶、双酶和部份酶解片段的分析,建立了三索线蛇及过树容蛇肝mtDNA的限制酶图谱。     

Molecular cloning and expression of Pfu DNA polymerase gene and its application in long-distance PCR

A 2.3 kb DNA fragment containing Pfu DNA polA gene was amplified by PCR from total DNA of Pyrococcus furiosus and cloned into a pGEM-T vector. The recombinant clone pT-pfu was digested with Nco I and Xho I and the fragment was inserted into an expression vector pET3d-X. The Pfu polA gene was expressed in Escherichia coli BL21 (DE3). The gene product (Pfu) was purified with heat denaturation, polyethylenemine (PEI) precipitation and Bio-rex 70 ion-exchange chromatography. The recombinant Pfu was verified by protein N-terminal sequencing. With the recombinant Pfu, large λ DNA fragments were successfully amplified in long-distance PCR.