中华大蟾蜍精巢组织全长cDNA文库的构建及泛素延伸蛋白基因Bg-ubi52的获得

运用SMART技术构建了中华大蟾蜍(Bufo bufo gargarizans)精巢全长cDNA文库。提取中华大蟾蜍精巢总RNA,用Clontech公司SMARTTM cDNA文库构建试剂盒反转录合成第一链cDNA,LD-PCR扩增获得全长cDNA双链;经SfiⅠ酶切、层析柱分离后,500bp以上的片段与λTriplEx2载体连接并包装,建成原始文库。经鉴定,原始文库滴度为2.21×106pfu/ml,重组率为91%;文库扩增后的滴度为2.94×109pfu/ml,重组率为93.7%。插入片段大小分布于0.4~2.0kb之间,平均长度约为1.0kb,说明已构建文库质量较高,为进一步筛选、克隆精巢特异表达基因奠定了基础。从该文库中克隆到了泛素延伸蛋白基因,全长561bp,包含完整的5′和3′非编码区,编码128个氨基酸,即泛素的76个氨基酸后融合了52个氨基酸的核糖体L40蛋白。     

毛冠鹿大脑组织全长cDNA文库构建

运用SMART技术构建了毛冠鹿(Elaphodus cephalophus)大脑组织全长cDNA文库。提取大脑组织总RNA,Oligotex mRNA Kit纯化、获得poly(A) RNA,以CDSⅢ/3′PCR引物进行逆转录,LD-PCR扩增获得全长双链cDNA,经SfiⅠ酶切及柱层析分离后,500 bp以上的片段与载体λTripIEx2连接,体外包装得到cDNA文库。经鉴定原始文库滴度为5.1×105pfu/ml,扩增后文库滴度为1.5×109pfu/ml,重组率达到85%以上,插入片断平均长度约为1.0 kb,说明构建文库质量符合要求,可用于大脑特异表达基因的筛选。从该文库中克隆到了rig基因全长,包含5′和3′非编码区,从第43至477个核苷酸为一完整阅读框(ORF),此阅读框可编码一个145氨基酸的rig蛋白。     

盐生植物海马齿盐胁迫全长cDNA文库的构建与分析

为了研究盐生植物耐盐基因表达调控,本实验以海水浇灌的海马齿植株为供试材料,构建了盐胁迫下的全长cDNA文库。构建方法如下:采用改良的CTAB法提取总RNA,SMART法反转录合成cDNA,LD-PCR方法合成双链cDNA。LD-PCR产物经蛋白酶K消化和SfiⅠ酶切后,经CHROMA SPIN+TE-1000分离柱子除去小片段DNA后,回收0.5kb以上的片段,按照适当的比例连接λTripIEX2载体。连接产物利用MaxPlaxTMLambda Packaging Extracts进行体外包装,得到海马齿初级cDNA文库。初始文库的独立克隆数为2.4×106pfu,初级文库滴度大于4.80×106pfu/mL,重组率为93.75%,插入片段为0.5～5kb,扩增文库的滴度为1.21×109pfu/mL,所得文库质量较高。本研究表明该cDNA文库适合于盐生植物海马齿相关基因的克隆和分析。     

草豆蔻cDNA文库的构建及鉴定

以草豆蔻花序原基为材料,构建了cDNA文库。原始文库滴度为0.8×106pfu/mL,扩增后滴度为4.23×1011pfu/mL。插入片段大小在500bp～1.5kb之间,重组率为95.3%。以水稻RAP1A基因中包含MADS-box保守区段的序列为探针对该文库进行筛选,获得的阳性克隆经测序及序列比对分析,确认其中共有10个含MADS-box的阳性克隆。     

星星草cDNA文库构建和金属硫蛋白(MT-1)基因的克隆

以受NaHCO3胁迫后的星星草叶片组织为材料构建了cDNA文库,文库的初始滴度为2.0×106pfu,重组率为95%,平均插入片段长度为0.8kb,扩增后文库的滴度为4.0×109pfu.mL-1.文库克隆随机测序获得了星星草的金属硫蛋白(MT-1)基因的全长cDNA序列,显示文库中含有一定量的全长基因.MT-1基因全长622bp,其中5'非翻译区57 bp,3'非翻译区343 bp,开放读码框长222 bp,编码73个氨基酸,氨基酸序列中具有植物MT-1蛋白特有的金属响应元件(MRE)序列,MT-1蛋白的分子量为7.814 kD,理论等电点为4.72.     

巨型艾美耳球虫孢子化卵囊cDNA文库的构建

为构建巨型艾美耳球虫(Eimeria maxima)孢子倾卵囊cDNA表灰文库,从E.maxima孢子化卵囊中提取总RNA,以总RNA为模板、λTriplex2TM为栽体,利用SMARTTM cDNA文库构建试剂盒构建全长cDNA表达文库.经测定构建的E.maxima cDNA表达文库的原始文库容量为1×106 pfu/ml,扩增后的文库滴度为5×1010pfu/ml,重组率为95%,插入片断主要集中在0.5～1kb之间.根据已知序列设计引物,能从文库中扩增出编码E.maxima免疫球蛋白重链结合蛋白的基因序列片段.结果 表明所构建的E.maxima cDNA表达文库质量良好,为克隆、筛选E.maxima的功能性基因奠定了基础.     

淫羊藿花蕾cDNA文库的构建与鉴定

基于sm art技术构建了淫羊藿花蕾cDNA文库并检测了其质量。结果表明,该文库重组率为95%,平均插入片段大小为1095 bp,文库滴度为2×106pfu/mL,是一个高质量的淫羊藿花蕾cDNA文库。此文库的建立将有助于克隆与次生代谢相关的基因,特别是淫羊藿黄酮特异合成代谢的基因,其次是克隆与花发育相关的基因。     

红果人参叶中cDNA文库的构建

以四年生红果人参叶片为材料,提取叶中总RNA合成cDNA,连接到质粒载体pDNR-LIB上。采用电穿孔法将重组质粒转化到DH5α中。经文库质量鉴定表明:原始文库滴度为1.008×106pfu·mL-1,扩增后的文库滴度为2.968×109pfu·mL-1,重组率接近100%,插入片段大小在0.5~2kb之间,平均为0.85kb,表明已成功构建了红果人参叶中cDNA文库。     

蒙古沙冬青冷冻胁迫SMART cDNA文库的构建及序列分析

以强抗逆植物蒙古沙冬青 (Ammopiptanthus mongolicus)为材料,用SMART技术构建了其在冷冻胁迫下的全长cDNA文库。原始文库滴度为9.44?06 pfu.mL-1,重组率为98.3%,插入片段长度在0.5~2.5kb,平均达到1kb。扩增文库滴度为1.98?010pfu.mL-1。从原始文库中随机挑取480个阳性克隆进行序列分析,获得348个Unigene,其中有些是逆境应答相关基因和新基因。此外,以扩增文库为模板,经PCR方法克隆到读码框为1083bp的沙冬青类RD22基因。这些结果表明所建文库质量较高,可以满足后续研究的要求。     

Construction of cDNA library and preliminary analysis of expressed sequence tags from Siberian tiger

In this study we successfully constructed a full-length cDNA library from Siberian tiger, Panthera tigris altaica, the most well-known wild Animal. Total RNA was extracted from cultured Siberian tiger fibroblasts in vitro. The titers of primary and amplified libraries were 1.30×10(6) pfu/ml and 1.62×10(9) pfu/ml respectively. The proportion of recombinants from unamplified library was 90.5% and average length of exogenous inserts was 1.13 kb. A total of 282 individual ESTs with sizes ranging from 328 to 1,142 bps were then analyzed the BLASTX score revealed that 53.9% of the sequences were classified as strong match, 38.6% as nominal and 7.4% as weak match. 28.0% of them were found to be related to enzyme/catalytic protein, 20.9% ESTs to metabolism, 13.1% ESTs to transport, 12.1% ESTs to signal transducer/cell communication, 9.9% ESTs to structure protein, 3.9% ESTs to immunity protein/defense metabolism, 3.2% ESTs to cell cycle, and 8.9 ESTs classified as novel genes. These results demonstrated that the reliability and representativeness of the cDNA library attained to the requirements of a standard cDNA library. This library provided a useful platform for the functional genomic research of Siberian tigers.     

Molecular cloning and characterization of pigeon (Columba liva) ubiquitin and ubiquitin-conjugating enzyme genes from pituitary gland library

In the study of the regulation of incubation, broodiness and laying performance in pigeons (Columba liva), a cDNA library, which was enriched with full-length brooding-related genes, was constructed by SMART LD-PCR techniques using the pituitary glands of incubating White King pigeons. The titers of optimal primary libraries were 1.54×10⁶ pfu/mL and 1.80×10⁶ pfu/mL and the titers of amplified libraries were 1.89×10⁸ pfu/mL and 2.32×10⁹ pfu/mL. The percentages of recombinant clones of primary libraries and amplified libraries were all over 90%. A positive clone was sequenced and named ubiquitin based on the highly similar from other species. The fragment has the four initial codons of ATG, a termination codon of TAA and a signal sequence of AATAAA for adding the poly-A tail. The open reading frame of 918bp encodes 305 amino acids (NCBI accession number is {"type":"entrez-nucleotide","attrs":{"text":"EU981283","term_id":"197693971","term_text":"EU981283"}}EU981283). Recombinant pigeon ubiquitin protein was efficiently expressed with the form of insoluble inclusion bodies in E. coli BL21 transformed with a pET28a⁺ expression vector containing the DNA sequence encoding mature pigeon ubiquitin. The molecular weight of expressed protein is the same as predicted size of approximately 35kD. To improve the efficiency of cloning full-length cDNA, strategies of RACE combined with cDNA library were used. The length of pigeons ubiquitin-conjugating enzyme gene obtained was 1263 bp containing a complete open reading frame of 435 bp that encodes 144 aa (NCBI accession number is {"type":"entrez-nucleotide","attrs":{"text":"EU914824","term_id":"197130954","term_text":"EU914824"}}EU914824). The results of this study not only provide a starting point for further study of ubiquitin function in pigeon species, but also provide a starting point for investigating the brooding mechanisms of pigeons.     

元江普通野生稻叶片cDNA文库的构建及部分基因片段分析

首次利用SMARTTM技术构建了中国普通野生稻中最原始类型——元江普通野生稻生长旺盛时期叶片的cDNA文库。该cDNA文库未扩增和扩增后的滴度分别为1.1×10⁶ pfu/mL和3.98×10⁷ pfu/mL, 重组率为91%, 插入片段大小为500～2 000 bp。测定的部分cDNA序列进行BLAST比较, 发现这些cDNA片段与日本晴栽培稻同源性很高, 达到98%以上。本研究为进一步分析这些cDNA片段的结构、功能和探讨元江普通野生稻在栽培稻演化中的地位奠定了基础。     

莱芜猪肝脏组织全长cDNA文库的构建和鉴定

目的:构建莱芜猪肝脏组织全长cDNA文库,以便研究与莱芜猪优良性状相关的基因。方法:采用改良的异硫氰酸酸胍一步法制备总RNA;利用SMART技术,以PrimeScript反转录酶逆转录合成第一链cDNA,通过LD-PCR扩增获得cDNA双链;经蛋白酶K消化和CHROMA SPIN-400柱分级分离后,收集500 bp以上的cDNA片段,并与pMD18-T载体连接,转化大肠杆菌DH5α感受态细胞,建成原始文库;随机挑取单菌落,用HindⅢ和EcoRⅠ进行双酶切鉴定重组子插入片段大小。结果:经鉴定,原始文库的滴度为2.8×105 cfu/mL,重组率约为98%,插入片段大小为0.5～2 kb,平均插入片段长度大于1 kb。结论:建立的cDNA文库质量良好,可以用于目的基因的筛选。