野生－粒小麦着丝粒RCS1相关序列的克隆鉴定

用水稻着丝粒重复序列RCS1为探针，与3072个克隆进行菌落杂交，得到了32个阳性克隆，用RCS1与拟斯卑尔脱山羊草着丝粒重复序列Tcs250为探针进一步筛选，在32个RCS1相关的阳性克隆中任选10个克隆进行点杂交，分别有6个和5个阳性克隆．为了克隆RCS1相关片段，依据RCS1的序列设计了三对引物，将引物3从上述阳性克隆中扩增的一个543bp的片段克隆测序，发现与水稻RCS1部分片段达到约83％的同源，与大麦的反转座子(Ty3／gypsy)部分序列同源性达到了92％，与节节麦中着丝粒的整合酶基因部分序列同源性达到了96％，命名为TBRCS1．TBRCS1可能是野生一粒小麦着丝粒区的组成部分．     

着丝粒串联重复序列RCS2对亚洲栽培稻和非洲栽培稻的比较分析

为了揭示中高度重复序列在同为AA基因组的亚洲栽培稻和非洲栽培稻基因组中的差异以及重复序列在.栽培稻种的分化过程中可能起到的作用,利用水稻着丝粒串联重复序列RCS2作为探针分别对籼稻广陆矮4号、粳稻日本晴和非洲栽培稻的体细胞染色体进行荧光原位杂交(FISH)实验,并对其核型进行同源性聚类和比较分析,杂交结果显示:RCS2序列位于在3种栽培稻染色体组中,RCS2序列位于每条染色体的着丝粒位置,但有不同的分布特点,表明该3种栽培稻基因组的RCS2序列有不同的进化方向.探讨了RCS2序列结合Cot-1 DNA FISH方法对水稻染色体组进行核型分析的可行性和优势.     

克隆含有MT-Ⅰ和MT-Ⅱ基因的染色体DNA片段及其内切酶图谱的鉴定

用小鼠MT-ⅠcDNA作为探针,从129小鼠的基因组库中获得含MT-Ⅰ基因的DNA片段。从6.8×10⁵的噬菌斑中挑出4个阳性噬菌体克隆,分别命名为1-1, 2-1, 1-6和4-3。在这4个克隆中1-1和2-1的阳性信号更强些。应用插入片段的末端引物作为探针进行杂交结合部分酶切的方法,对这2个克隆的插入片段进行了限制性内切酶酶切图谱分析,确定了克隆1-1和2-1的酶切图谱及MT-Ⅰ基因在2个克隆DNA中的位置。并进一步发现和证明了在2个克隆中含有MT-Ⅱ基因。     

人染色体17q12区雨330kb范围内表达顺序的筛选

用定位于人染色体17q12区带的长约330kbYAC克隆500D09（取自法国人类多态性研究中心YAC库）作为杂交探针，筛选人骨髓、胎脑、胎肾、骨骼肌和睾丸等五种组织的cDNA库（2×105～3×105pfu／库），从中获得102个初级阳性克隆．初级克隆经PCR扩增，分别与人基因组DNA、酵母基因组DNA和人rDNA探针作dotblot杂交分析，排除其中假阳性克隆后，复筛得到32个候选克隆．对其中2个候选克隆B4511和S5511分别测定143bp和147bp序列．经查新和同源性分析，这两个片段与已知基因的同源性均小于50％，提示它们可能是来自于新基因的表达顺序．     

青海牦牛与云南牦牛乳球蛋白基因5′调控区核苷酸序列同源性比较

利用一对PCR引物,寡聚核苷酸序列的上游引物为5-′gCg,AAT,TCA,TCC,CAC,gTg,CCT,gC-3;′下游引物为5-′gAg,AAT,TCC,Tgg,ggA,ggg,ACC,TT-3′。经68℃退火及30轮循环的PCR程序后,分别克隆来自我国青海和云南地区牦牛的乳球蛋白基因的5′调控区1 447 bp的DNA片段。将该片段从琼脂糖凝胶中回收,克隆在pMD18-T Vector后进行序列测定。序列分析结果表明,青海牦牛该序列的核苷酸序列与文献报道的奶牛该基因的同源性为97.65%,云南牦牛该序列的核苷酸序列与奶牛该基因的同源性为96.8%,青海牦牛与云南牦牛该基因片段的核苷酸序列同源性为99.4%。     

水稻硝酸还原酶基因5′上游序列的克隆与序列分析

以日本晴水稻幼苗叶的基因组总DNA为模板,采用PCR方法扩增获得约1 300 bp大小的DNA片段,回收该片段并与pMD18-T载体连接,转化大肠杆菌感受态,并提取质粒DNA.用凝胶电泳检测和酶切鉴定,选取阳性克隆进行测序分析.测序结果显示,该片段含1 376个核苷酸对;应用NCBI网站的BLAST软件对本试验中克隆的序列与GenBank(NC_008401)公布的水稻硝酸还原酶基因启动子序列进行比对,有3个核苷酸差异,同源性为99%,证实本试验中克隆的DNA序列为水稻硝酸诱导基因启动子.该序列含有多个与转录调控有关的保守序列(如TATA-box、CAAT-box和GAGA-box).此序列的成功克隆,为今后开展水稻等重要农作物转基因研究奠定基础.     

水稻S_5区候选克隆R2I19的筛选及序列信息学分析

以水稻广亲和品种Cpslo17为材料 ,构建了一个覆盖 9倍核基因组的cosmid文库 ,其平均插入片段约4 0kb。以与广亲和位点紧密联锁的单拷贝分子标记BAC2 3D12的R末端为探针 ,从cosmid文库中筛选得到一个阳性克隆R2I19(～ 32kb)。结合S5位点的高密度连锁图和物理图谱 ,初步确定为S5区候选克隆。对该克隆的 2个TAC亚克隆TRW15 10 (～ 15kb)及TRW15 17(～ 15kb)进行了初步的生物信息学分析 ,证实与已知的水稻基因组序列有很高的同源性 ,并显示其中可能含有与水稻育性相关的基因。     

编码普通野生稻磷酸盐转运蛋白基因片段的分离与克隆

以云南普通野生稻基因组DNA为模板，根据GeneBank中登记的编码小麦高亲和力磷酸转运蛋白基因保守序列设计一对特异引物，利用多聚酶链反应技术（PCR），扩增出目标基因（cwrpt)1002bp长度的基因片段并克隆到载体pGEM-T。经DIG标记探针杂交检测初筛，限制性内切酶酶切，PCR扩增，DNA序列分析与可能氨基酸序列同源性比较，此推定的氨基酸序列与小麦，水稻，拟南芥，番茄磷酸转运蛋白同源性很高，初步认为此基因片段为普通野生稻耐低磷胁迫相关磷酸盐转运蛋白的编码基因，获得全长序列与基因表达的进一步研究正在进行中。     

藏羚羊(AAC)_n微卫星富集文库构建与引物筛选

基于磁珠富集法,利用生物素标记的寡核苷酸探针(AAC)8从藏羚羊(Tibetan antelope)基因组酶切的300~1000bp片段中筛选微卫星位点,纯化的富集片段连接到pCR@2.1载体和转化到Trans5α感受态细胞.随机挑取180个白斑克隆,PCR检测到条带数大于或等于2的阳性克隆为56个,阳性率为31.1%.对阳性克隆测序,获得43条含微卫星座位的序列,微卫星重复次数在5~20次之间.舍弃不适宜设计引物的微卫星座位,试验设计并合成了20对微卫星引物;以3个样点(青海、新疆、西藏)的24个藏羚羊基因组为模板进行PCR扩增,获得8对可得到稳定扩增产物的微卫星引物,其中4对引物的扩增产物具有多态性,座位分别为AAC050、AAC056、AAC165和AAC477.上述引物可用于藏羚羊及近缘物种的遗传多样性、种群遗传结构等研究.     

RLM-RACE法快速克隆盐角草胆碱单加氧酶cDNA 5′末端全序列

采用RLM-RACE法,根据已获得的盐角草胆碱单加氧酶基因的部分序列,设计2条特异性嵌套PCR引物,成功地克隆了该基因cDNA 5′末端全序列,测序结果显示该片段包括5′UTR 154个核苷酸和编码区606个核苷酸,编码N端202个氨基酸,Blast P结果表明,该片段编码的蛋白序列与辽宁碱篷及其他藜科植物的胆碱单加氧酶同源性达到85％以上,同时找出了其转录起始位点,即为该序列的第1个碱基g．     

Physical location of riceGm-6, Pi-5(t) genes inO. officinalis with BAC-FISH

A fluorescence in situ hybridization (FISH) procedure was adopted to physically map two rice BAC clones 24E21 and 4F22 linked to Gm-6 and Pi-5(t) in O. offi-cinalis. FISH results showed that the two BAC clones were located at 4L. The percentage distance from the centromere to the hybridization sites was 72 + 2.62 for 24E21 and 54+ 5.43 for 4F22, the detection rates were 52.70% and 61.2%. The results obtained from the BAC and plasmid clones, RG214 and RZ565 of cultivated rice and O. officinalis were the same. This suggested that the markers, RG214 and RZ565 of cultivated rice and O. officinalis were in the same BAC clones. The homologous sequences of Gm-6 and Pi-5(t) in O. officinalis were positions that signals existed on the 4L. Many signals were observed when no Cot-1 DNA blocked. This also showed that repetitive sequences were some ho-molgous between cultivated rice and O. officinalis. The identification of chromosome 4 of O. officinalis is based on Jena et al. (1994). In our study, we discussed the possibility of physical map in O. officinalis with rice BAC clones.     

王锦蛇(Elaphe carinata)Sox基因保守区的克隆及测序

参照人SRY基因HMG-box保守区序列设计一对兼并引物,PCR扩增了王锦蛇的Sox基因,采用SSCP技术筛选阳性克隆,并对其进行了测序.结果在雌雄个体中共筛选出4个Sox基因,其中一个为雌性独有,显示出性别差异性;4个Sox基因DNA序列及编码的氨基酸序列与人相应SOX基因的相似性分别为91%、91%、92%、91%和96%、98%、96%、96%,显示出高度的保守性.实验结果为王锦蛇的性别决定机制研究提供了分子资料.     

Screening and Insert Size Analysis of Candidate C-Genome BAC Clones from Brassica napus

Thirty-two C-genome specific candidate bacterial artificial chromosome (BAC) clones were successfully screened from the BAC library by four-dimensional PCR method with the primer pairs of 75 simple sequence repeat (SSR) markers located in the nine C-genome linkage groups of Brassica napus. The screened 32 BAC clones have an average insert size of 114.2 kb with a range of 30-190 kb. They are the first set of C-genome BAC clones screened from B. napus genomic BAC library. The average insert size of this set of BAC clones presented that the constructed BAC library had a high quality. This set of BAC clones can be used as markers to identify individual chromosomes of B. napus C-genome.     

Xenorhabdus nematophilus BP品系杀虫毒素基因的克隆与鉴别

构建了昆虫病原线虫共生菌Xenorhabdus nematophilus BP品系的粘粒文库并用生物测定的方法从中筛选到2个对棉铃虫初孵幼虫有口服抑杀作用的克隆cos83和cos76。为初步确定这两个克隆的毒素基因与已报道基因的差异程度，根据已发表的共生菌毒素基因序列资料设计了7对引物对这两个克隆进行PCR扩增并对扩增产物进行测序和分析。从毒力较强的cos83中，7对引物均扩增出与目标片段大小一致的产物，而从cos76中只有5对扩增到目标片段。测序结果显示，cos76的5个PCR扩增产物与cos83的对应扩增产物DAN序列同源性为100％。以cos83的7个PCR扩增产物所编码氨基酸序列进行BLAST分析，它们与X．nematophilus PMF1296和Photorhabdus luminencenc W14毒素相应区间的平均同源性分别为94％和58％，说明cos83毒素是共生菌口服毒素家族的一员但与同类的其它毒素有一定的差异，值得对其杀虫谱，作用机理等进行进一步的研究。     

猴空泡病毒(SV40)PCR检测方法的建立与初步应用

目的建立检测实验猴及生物制品中猴空泡病毒(SV40)的PCR方法。方法根据SV40-776株设计合成三对引物对现有毒株进行PCR扩增并克隆测序。用这三对引物对56份猴肾、肺、脾及10批脊髓灰质炎疫苗进行检测。结果三对引物均扩增出目的片段;56份猴脏器和10批疫苗SV40检测均为阴性。结论56只恒河猴和10批疫苗中未检测到SV40,所设计的三对引物检测结果准确,均可用于检测。     

Cupriavidus metallidurans CH34中2个苯酚降解基因簇的筛选与功能鉴定

Cupriavidus metallidurans(C.metallidurans)CH34是一种重金属耐受性细菌,能在以苯酚、甲苯酚、苯甲酸、苯胺等芳香族化合物为唯一碳源和能源的培养基中生长,其基因组中含有2个苯酚降解基因簇.以载体pIndigo-BAC 5构建C.metallidurans CH34的细菌人工染色体(bacterial artificial chromosome,BAC)文库,获得约3万个克隆,平均插入片段大小为30 kb,插入频率为98%,推测该文库覆盖CH34基因组约1 240倍.用PCR筛选文库中的3 000个单克隆,共获得9个阳性克隆,其中5个克隆含有长基因簇,4个含有短基因簇,并从中得到含有全长苯酚降解基因簇的克隆.利用以苯酚为唯一碳源的无机盐培养基,研究2个基因簇在大肠杆菌中的表达情况.结果显示,两个基因簇均表现出了苯酚降解能力,短簇的降酚能力要优于长簇.     

Determination of copy number for 5S rDNA and centromeric sequence RCS2 in rice by Fiber-FISH

The copy number of 5S rDNA and centromeric sequence RCS2 was determined by extended DNA fiber based fluorescence in situ hybridization (Fiber-FISH) in rice (Oryza sativa ssp. indica cv. Guangluai No. 4) genome. In order to determine the copy number, it is necessary to know the basepair number that a given length DNA fiber contains under a microscope. Therefore, the length of two DNA fragments, in which the basepair number had been already known, was measured. The insert sequence of the tested BAC 38D17 was 136 kb and its extended DNA was 56.4 μm long, 2.41 kb/μm on average, while that of the tested BAC 44B4 was 144.5 kb in total and 55.7 μm long, 2.60 kb/μm on average under the microscope. They were very close to the theoretical value of B-DNA in the Watson-Crick DNA model, which is 2.97 kb/μm. According to the average value of basepair number per μm of the two samples mentioned above, that is, 2.51 kb/μm, it could be estimated that the copy number was about 686 for 5S rDNA and 286-1121 for the centromere sequence RCS2.     

盐藻（Dunaliella viridis）细菌人工染色体文库的构建和鉴定

盐藻具有极强的耐盐能力，是研究植物耐盐机制的模式系统.为了对其耐盐机制进行深入的 研究，以pCC1BAC为载体，构建了盐藻的细菌人工染色体（BAC）文库.该文库共有9 216 个转化子，插入片段平均长度为55 kb，以单克隆形式保藏在96块96孔板中，并建立了四维P CR基因筛选体系，可以通过4轮PCR快速筛选获得阳性单克隆.根据本实验室分离到的两个盐 藻基因的cDNA序列（ DvSPT2和DvTPSP ）设计引物，通过PCR从该文库中各筛到4个阳性BA C克 隆，说明该文库能有效用于分离盐藻基因的基因组序列，据此推测该文库约覆盖4倍盐藻基 因组序列.     

Construction of a BAC library from cucumber （Cucumis sativus L.） and identification of linkage group specific clones

A bacterial artificial chromosome （BAC） library consisting of 19,200 clones with an average insert size of 105 kb has been constructed from a cucumber （Cucumis sativus L.） inbred line S94, derived from a cultivar in North China. The entire library was equivalent to approximately 5 haploid cucumber genomes. To facilitate chromosome engineering and anchor the cucumber genetic linkage map to its chromosomes, 15 sequence-characterized amplified regions （SCAR） and seven simple sequence repeats （SSR） markers from each linkage group of cucumber were used to screen an ordered array of pooled BAC DNA with polymerase chain reaction （PCR）. Fifteen markers gave at least two positive clones. As a result, 22 BAC clones representing 7 linkage groups of cucumber were identified, which further validated the genome coverage and utility of the library. This BAC library and linkage group specific clones provide essential resources for future research of the cucumber genome.     

Construction of a BAC library from cucumber (Cucumis sativus L.) and identification of linkage group specific clones

A bacterial artificial chromosome (BAC) library consisting of 19,200 clones with an average insert size of 105 kb has been constructed from a cucumber (Cucumis sativus L.) inbred line S94; derived from a cultivar in North China. The entire library was equivalent to approximately 5 haploid cucumber genomes. To facilitate chromosome engineering and anchor the cucumber genetic linkage map to its chromosomes, 15 sequence-characterized amplified regions (SCAR) and seven simple sequence repeats (SSR) markers from each linkage group of cucumber were used to screen an ordered array of pooled BAC DNA with polymerase chain reaction (PCR). Fifteen markers gave at least two positive clones. As a result, 32 BAC clones representing 7 linkage groups of cucumber were identified, which further validated the genome coverage and utility of the library. This BAC library and linkage group specific clones provide essential resources for future research of the cucumber genome.