Construction and characterization of a bacterial artificial chromosome library of peach

This report briefly describes the construction and characterization of a peach [ prunus persica (L.) Batch] Var. Jingyu bacterial artificial chromosome (BAC) library. The variety Jingyu has many important agronomic characters of stone fruits, and it is a main parent in Chinese peach breeding. After cloning of the high molecular weight peach DNA into pBeloBAC 11, we obtained over 22 000 recombinant clones. The BAC library has an average insert size of 95 kb and represents approximately 7 times peach haploid genome equivalents. After being screened with two randomly amplified polymorphic DNA markers, W4 and P20, which are linked to yellow flesh and nectarine genes of peach respectively, ten positive clones have been detected. This library is very useful for map-based cloning of peach genes and physical mapping of peach genome.     

Construction of a bacterial artificial chromosome library of S-type CMS maize mitochondria

In order to isolate mitochondrial genes easily, we have developed a new method to construct S-type CMS maize mitochondrial gene library by means of embedding mitochondria and enzymatic digesting mitochondriain situ, preparing mtDNA by electrophoresis, digesting LMP agarose with β-agarase, using BAC vector and electroporation. About 2 500 white clones of Mo17 CMS-J mitochondrial gene library were obtained with the average size of 18.24 kb, ranging from 5 to 40 kb, 63.6% inserts came from mitochondrial genome and represented 48 × mitochondrial genome equivalents. All the probes had detected the positive clones in the gene library. It is helpful to elucidating the maize mitochondrial genome structure and mechanism of S-type CMS, and may give some valuable reference to the construction of other plant mitochondrial genome library.     

Construction and characterization of a bacterial artificial chromosome library of rice 5460F

Thermo-sensitive genie male sterile (TGMS) rice has a number of desirable characteristics for hybrid rice production. Many studies have demonstrated that the sterility of TGMS rice is controlled by a single recessive gene. It has been mapped for the first time on chromosome 8 and namedtms 1. Several AFLP markers which tightly linked to thetms 1 gene have been identified recently. In order to develop a detailed physical map of thetms1 gene-encompassing region and finally clone thetms1 gene, a bacterial artificial chromosome (BAC) library of rice 5460F (the fertile mutant line of TGMS rice 5460S) using a modified vector pECBAC1 has been constructed. The constructed 5460F BAC library consists of 16 896 clones with an average insert size of 119 kb, which represents about 4.7 times rice haploid genome equivalents. Neither chloroplast nor mitochondrial DNA was detected from the library. The library was screened with three single copy sequence amplified fragment length polymorphism (AFLP) markers which tightly linked totms1 gene as probes and eight positive clones were identified.     

A five-fold pig bacterial artificial chromosome library: a resource for positional cloning and physical mapping

A pig BAC library was constructed with genomic DNA from a male Erhualian pig. After partial digestion with Hind III or BamH I the fragments obtained were cloned into the pBeloBAC11 vector. The library consists of 184320 clones which stored in 480 pieces 384-well plates (20 plates per superpool). A two-step 4-dimension PCR screening system was established to screen the positive clones. An average insert size of 128 kb was estimated from 105 randomly isolated clones, which indicates that the library is more than five times of genomic coverage. For the demonstration of the probability to pick out any unique genes or DNA markers from the library, 10 single-copy genes were screened out and the positive clones were yielded between 1 and 8 with an average of 3.6. Positive superpools were obtained for 32 microsatellite markers selected from different regions of pig genome. The number of positive superpools for each marker varies from 1 to 9 with an average of 4.78. This BAC library provides an additional resource for pig physical mapping and gene identification.     

Development of Gossypium barbadense chromosome segment substitution lines in the genetic standard line TM-1 of Gossypium hirsutum

Chromosome segment substitution lines (CSSL) consist of a battery of nearisogenic lines that have been developed and cover the entire genome of some crops. With the exception of one homozygous chromosome segment transferred from a donor parent, the remaining genome of each CSSL line is the same as the recipient parent. It is an ideal material for genome research and particularly QTL mapping. In the present study, we first developed one set of CSSL lines using G. hirsutum acc. TM-1 (the genetic standard), as the recipient parent and G. barbadense cv. Hai7124 as the donor parent using molecular assisted-selection in BC5S1-3 generations. The CSSL consisted of 330 different lines, in which 1-4 different lines had the same or overlapping substituted segments. The genetic length of the substituted segments covered 5271.9 cM with an average segment distance of 10.9 cM, 1.5 times the total genetic length of Upland cotton (3514.6 cM). The substituted segments of each line varied in length, ranging from 3.5 cM for the shortest segment to 23.2 cM in the longest segment. Our CSSL have not yet to cover the entire tetraploid cotton genome, due to the absence of some donor parent interval segments.     

噬菌体抗体库的构建

噬菌体抗体库技术是近年来非常活跃的一个研究领域,本文主要讨论噬菌体抗体库构建中一些关键的问题。     

噬菌体抗体库的构建

噬菌体抗体库技术是近年来非常活跃的一个研究领域．本文主要讨论噬菌体抗体库构建中一些关键的问题．     

麻疯树胚乳cDNA文库的构建与分析

以等质量比的不同发育阶段的麻疯树（Jatropha curcas L.）胚乳为材料构建麻疯树胚乳cDNA文库.初级文库滴度为1.5×106 Pfu/mL,重组率为99.7％,插入片段大小为0.4～4 kb,平均约1 kb.全长基因的比例达到20％.推测的蛋白质序列种类主要包括贮存蛋白相关、转录表达调控相关、脂肪酸合成相关及信号传导相关等同源基因序列.编码功能基因的类型与分布情况同Joseph A White等构建的蓖麻胚乳cDNA文库基本一致,个别类型如贮存蛋白合成相关基因的比例相比较低,信号传导     

一种改进细菌觅食算法的模糊控制规则库设计

模糊控制规则库的建立决定了模糊控制系统的性能,而在能源生产、机器人控制等领域中对控制精度要求越来越高,使得常规的模糊控制规则库建立方法有时不再适用。为此,提出一种新型的基于集群智能算法的改进细菌觅食算法IBFO(improved bacterial foraging optimization)来改进规则库的建立过程,剖析了依据人工经验归纳来制定模糊规则库的不完善性,描述了对改进型的模糊控制系统的构建步骤,优化了改进型TSK(takagi-suegeno-kang)模糊系统C-ATSKFS(constant-ameliorative TSK fuzzy system)规则库的高斯隶属函数参数。通过与现有的规则库建立方法相比对,可知改进算法能有效地提高模糊控制系统的识别精度。MATLAB仿真结果表明:提出的新型细菌觅食算法对模糊控制规则库的建立具有较高的实用价值。     

Construction and characterization of a normalized whole-life-cycle cDNA library of rice

A cDNA library with genomic complete coverage is a powerful tool for functional genomic studies.For studying the functions of rice genes on a large scale,a normalized whole-life-cycle cDNA library is constructed based on the strategy of saturation hybridization with genomic DNA using rice cultivar Minghui 63,an elite restorer line for a number of rice hybrids that are widely cultivated in China,This library consists of cDNA from 15 directionally cloned cDNA libraries constructed with different tissues from 9 developmental stages.For normalization,the denatured plasmids purified from the 15 directionally cloned libraries are mixed and hybridized with saturated genomic DNA labeled with magnetic beads in two complementary systems. Well-matched plasmids are captured from the hybridized genomic DNA and electroporated into competent DH10B E. coli for construction of the normalized whole-life-cycle cDNA library.This library consists of 62000 clones with an average insert length about 1.4kb.Inverse Northern blotting shows that this cDNA library included many rarely expressed genes and tissue-specific genes.Sequencing of 10750 cDNA clones of this library reveals 6399 unique EST s(expressed sequence tags),indicating that the non-redundancy of the library is about 59.5%.This library has been used to make cDNA microarrays for functional genomic studies.     

Cloning of a representative genomic library of the human X chromosome after sorting by flow cytometry

A library of 50,000 recombinants representative of the human X chromosome has been constructed. Human X chromosomes were physically separated using a fluorescence-activated cell sorter. The DNA was purified from the chromosomes, digested to completion with the restriction enzyme EcoRI and cloned into the phage lambda gtWES.lambda B. The X-derived nature of the recombinants was confirmed by hybridization to rodent/human cell line DNA containing only the human X chromosome. Such libraries will be particularly useful for the investigation of genetic diseases such as Duchenne muscular dystrophy, where the basic defect has not been elucidated, and of neoplasia, where several specific chromosomal anomalies, particularly for the leukaemias, have been identified.     

棉花腺体形成时均一化cDNA文库的构建

为克隆筛选棉花腺体形成相关的基因,运用SMART技术构建cDNA文库.首先抽提棉花腺体形成时期的mRNA,mRNA逆转录后合成cDNA,经均一化处理后,SfiⅠ酶切,连接质粒载体,电转化,成功构建了棉花腺体形成时期的cDNA文库.经鉴定原始文库滴度为5.8×105 cfu/mL,其重组率高达94%,插入片段的平均长度约为1.4 kb.     

长叶苦竹新造林的生长发育规律研究

【目的】为揭示长叶苦竹(Pleioblastus chino var.hisauchii)新造林的生长发育规律,探究不同年龄竹株的秆形特征及不同龄级竹地下茎的鞭根生长情况,为长叶苦竹及其他混生型竹的栽培养护和经营管理提供参考。【方法】调查了南京林业大学溧水白马实验基地长叶苦竹新造林5年时的年龄结构和空间分布,标记整片竹林每株竹子的位置和年龄信息,随机选取3株1～5年生健康无病虫害竹株,测定其地径、株高、枝下高、每节节长和对应的节径等指标。追踪1～5年生竹鞭系,统计鞭段数、鞭节数、岔鞭数、芽数,测量鞭长、鞭径、鞭节长等指标。【结果】随着长叶苦竹新造林的更新,前4年新龄竹株数呈递增趋势。地径、株高和枝下高随竹龄的增长均呈递减趋势,且不同年龄竹株的地径和株高、枝下高和株高均存在线性正相关关系。竹秆每节节径由基部到梢部呈递减趋势,且每节节长和对应的节径存在线性正相关关系。新龄竹每节节径、每节节长、平均节径和平均节长均大于老龄竹。鞭径、总鞭长、鞭段数和芽数随竹龄的增长呈递减趋势。鞭长、鞭节长、岔鞭数和笋芽数随竹龄的增长呈先增后减的趋势,在造林第4年时达到最高。【结论】长叶苦竹新造林的年龄结构呈上...     

Construction of a linkage map and QTL mapping for fiber quality traits in upland cotton (Gossypium hirsutum L.)

With the development in spinning technology, the improvement of cotton fiber quality is becoming more and more important. The main objective of this research was to construct a high-density genetic linkage map to facilitate marker assisted selection for fiber quality traits in upland cotton (Gossypium hirsutum L.). A genetic linkage map comprising 421 loci and covering 3814.3 cM, accounting for approximately 73.35% of the cotton genome, was constructed using an F2 population derived from cross GX1135 (P 1 )×GX100-2 (P 2 ). Forty-four of 49 linkage groups were assigned to the 26 chromosomes. Fiber quality traits were investigated in F2 population sampled from individuals, and in F2:3 , and F2:4 generations sampled by lines from two sites and one respectively, and each followed a randomized complete block design with two replications. Thirty-nine quantitative trait loci were detected for five fiber quality traits with data from single environments (separate analysis each): 12 for fiber length, five for fiber uniformity, nine for fiber strength, seven for fiber elongation, and six for fiber micronaire, whereas 15 QTLs were found in combined analysis (data from means of different environments in F2:3 generation). Among these QTLs, qFL-chr5-2 and qFL-chr14-2 for fiber length were detected simultaneously in three generations (four environments) and verified further by combined analysis, and these QTLs should be useful for marker assisted selection to improve fiber quality in upland cotton.     

Construction of artificial chromosomes in yeast

Fifty-five-kilobase long artificial chromosomes containing cloned genes, replicators, centromeres and telomeres have been constructed in yeast. These molecules have many of the properties of natural yeast chromosomes. Centromere function is impaired on short (less than 20 kilobases) artificial chromosomes.     

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).     

浅谈高校数字图书馆的建设

科学技术的迅猛发展,计算机技术、现代通信技术、网络技术在图书馆自动化建设中的应用,改进和变革着图书馆传统的服务模式,加强数字化建设,建设数字化图书馆是时代的要求。介绍了图书馆的功能,探讨了图书馆的发展以及图书馆的利用,阐述了数字图书馆的具体内容。     

图书馆搬迁与图书馆环境建设

本文根据大庆师范学院图书馆自旧址迁入新馆的工作情况,论述了以搬迁为契机,营造新图书馆环境的方法对策。