No major schizophrenia locus detected on chromosome 1q in a large multicenter sample

Reports of substantial evidence for genetic linkage of schizophrenia to chromosome 1q were evaluated by genotyping 16 DNA markers across 107 centimorgans of this chromosome in a multicenter sample of 779 informative schizophrenia pedigrees. No significant evidence was observed for such linkage, nor for heterogeneity in allele sharing among the eight individual samples. Separate analyses of European-origin families, recessive models of inheritance, and families with larger numbers of affected cases also failed to produce significant evidence for linkage. If schizophrenia susceptibility genes are present on chromosome 1q, their population-wide genetic effects are likely to be small.     

Location of a major susceptibility locus for familial schizophrenia on chromosome 1q21-q22

Schizophrenia is a complex disorder, and there is substantial evidence supporting a genetic etiology. Despite this, prior attempts to localize susceptibility loci have produced predominantly suggestive findings. A genome-wide scan for schizophrenia susceptibility loci in 22 extended families with high rates of schizophrenia provided highly significant evidence of linkage to chromosome 1 (1q21-q22), with a maximum heterogeneity logarithm of the likelihood of linkage (lod) score of 6.50. This linkage result should provide sufficient power to allow the positional cloning of the underlying susceptibility gene.     

Locus of the alpha-chain of the T-cell receptor is split by chromosome translocation in T-cell leukemias

Mouse lymphoma cells were hybridized with two human acute T-cell leukemias with a t(11;14) (p13;q11) translocation and the segregated hybrids were examined for the presence of the DNA segments coding for the constant (C) and the variable (V) regions of the alpha chain (C alpha and V alpha) of the T-cell receptor. The C alpha segment was translocated to the involved chromosome 11 (11p+) while the V alpha segment remained on the involved chromosome 14 (14q-). The data indicate that the locus for the alpha chain of the T-cell receptor is split by the chromosomal breakpoint between the V alpha and the C alpha gene segments, and that the V alpha segments are proximal to the C alpha segment within chromosome band 14q11.2.     

我国易位少籽西瓜研究回顾与展望

文章回顾了我国易位少籽西瓜主要研究成果,分析了我国易位少籽西瓜产业现状,发现产业存在重视不够和研究攻关协作相对不足等一些问题,认为易位少籽是发展少籽西瓜的有效途径,发展前景很好,今后要加强基础性研究、新品种选育和品种保护。     

Cloning and genetic transformation of a novel rice gene OsAPT2

A novel rice gene OsAPT2,which encodes a putative adenine phosphoribosyl transferase(APRT),was cloned.Its full-length cDNA is 1125bp,composing an ORF encoding 212 amino acid residues and a stop cordon,a 5‘ UTR of 123 bp and a 3‘ UTR of 363 bp.The sequence data have been submitted to the DDBJ/EMBL/GenBank databases(accession number:AY238894).The deduced amino acid sequence of OsAPT2 is highly homologous to those of previously reported APRTs.The genomic OsAPT2 gene contains 7 exons and 6 introns.Its total len...     

Cloning and genetic transformation of a novel rice gene OsAPT2

A novel rice gene OsAPT2,which encodes a putative adenine phosphoribosyl transferase(APRT),was cloned.Its full-length cDNA is 1125bp,composing an ORF encoding 212 amino acid residues and a stop cordon,a 5' UTR of 123 bp and a 3' UTR of 363 bp.The sequence data have been submitted to the DDBJ/EMBL/GenBank databases(accession number:AY238894).The deduced amino acid sequence of OsAPT2 is highly homologous to those of previously reported APRTs.The genomic OsAPT2 gene contains 7 exons and 6 introns.Its total length is 4758 bp.Then,an antisense expression vector of the full-length OsAPT2 cDNA was constructed and transformed into rice variety Taibei309 by Agrobacterium tumefaciens mediated transformation method.In total,650 T0 transgenic plants were obtained based on both antibiotic screening and specific PCR identification.One hundred individuals of them were selected and planted in Hainan Island.From those 11 male sterile lines with seed-setting rate lower than 3% in bagged spike were obtained.Results suggest that OsAPT2 is involved in male sterility.Nine of the 11 male sterile lines were constitutive sterile lines;two of the 11 male sterile lines were thermo-sensitive genic male sterile lines,which may be useful in hybride rice breeding.     

Cloning of large segments of exogenous DNA into yeast by means of artificial chromosome vectors

Fragments of exogenous DNA that range in size up to several hundred kilobase pairs have been cloned into yeast by ligating them to vector sequences that allow their propagation as linear artificial chromosomes. Individual clones of yeast and human DNA that have been analyzed by pulsed-field gel electrophoresis appear to represent faithful replicas of the source DNA. The efficiency with which clones can be generated is high enough to allow the construction of comprehensive libraries from the genomes of higher organisms. By offering a tenfold increase in the size of the DNA molecules that can be cloned into a microbial host, this system addresses a major gap in existing experimental methods for analyzing complex DNA sources.     

Validation of qGSIO,a quantitative trait locus for grain size on the long arm of chromosome 10 in rice (Oryza sativa L.)

Grain size is a major determinant of grain weight and a trait having important impact on grain quality in rice.The objective of this study is to detect QTLs for grain size in rice and identify important QTLs that have not been well characterized before.The QTL mapping was first performed using three recombinant inbred line populations derived from indica rice crosses Teqing/IRBB lines,Zhenshan 97/Milyang 46,Xieqingzao/Milyang 46.Fourteen QTLs for grain length and 10 QTLs for grain width were detected,including seven shared by two populations and 17 found in one population.Three of the seven common QTLs were found to coincide in position with those that have been cloned and the four others remained to be clarified.One of them,qGS10 located in the interval RM6100-RM228 on the long arm of chromosome 10,was validated using F_(2:3) populations and near isogenic lines derived from residual heterozygotes for the interval RM6100-RM228.The QTL was found to have a considerable effect on grain size and grain weight,and a small effect on grain number.This region was also previously detected for quality traits in rice in a number of studies,providing a good candidate for functional analysis and breeding utilization.     

法氏囊炎病毒VP2基因高变区片段的克隆与鉴定

[目的]研究法氏囊病毒VP2蛋白的抗原表位在机体免疫应答中的作用和特点。[方法]以接种传染性法氏囊病毒(IBDV)的鸡胚尿囊液为模板,根据Genbank中登录的IBDV的VP2蛋白基因的全序列设计引物,通过RT-PCR扩增获得VP2高变区部分片段,将其克隆到原核表达质粒PGEX-4T-1中,经酶切鉴定后,转化大肠杆菌Rosetta(DE3)BL21,筛选阳性克隆并对其进行测序鉴定。[结果]通过PCR扩增获得一个504bp的扩增片段,序列分析结果表明它与GenBank中登录的IBDV的VP2蛋白基因的核苷酸序列同源性达99.8%,其氨基酸序列的同源性为99.4%,说明各毒株间高变区基因序列保守性很高。[结论]法氏囊炎病毒毒株在两个大小亲水区内的氨基酸都非常保守。     

番茄WRKY2基因的克隆(英文)

[目的]研究WRKY转录因子在番茄中的功能。[方法]根据已克隆的番茄WRKY转录因子片段设计引物,以100μmol/LJA处理6h后的番茄总RNA为模板,采用RT-PCR方法。[结果]从JA诱导的番茄幼苗中获得了608bp的cDNA片段,序列分析表明,该序列含有WRKYGQK保守结构域,与Capsicum annuum WRKY-c序列相似性是79%,与Nicotiana tabacum NtWRKY-7序列相似性是74%。[结论]已经成功克隆了番茄WRKY2基因片段。     

RFLP标记揭示的1RS/1BL易位系对小麦农艺性状的影响

以含1RS／1BL易位染色体的多小穗小麦新种质10-A和普通小穗小麦品系88-1463,及其与非1RS／1BL易位系小麦川育12构成的重组系为供试材料,选用4个RFLP标记和1个醇溶蛋白标记Gld1B3分析了1RS／1BL易位系对小麦农艺性状的影响。结果表明,1RS／1BL易位系的每穗小穗数目和株高均显著或极显著地高于非易位系,其千粒重略高于非易位系(p＜0.1),而每小穗结实粒数却显著低于非易位系。抽穗期、穗粒数和穗粒重几个性状间差异不显著。1RS／1BL易位染色体在增加每穗小穗数目的同时还具有降低每小穗结实粒数的作用,这可能是导致易位系和非易位系间穗粒数差异不显著的直接原因。     

福氏志贺菌主动外排基因acrB的克隆与序列分析

以福氏志贺菌2a型菌株基因组为模板,经PCR扩增得acrB基因,将该基因克隆到pMD18-T Vector载体,将重组质粒进行PCR和酶切鉴定及序列测定.结果表明:测定序列与Genbank收录的福氏志贺菌参考序列同源性为99.7%,与大肠杆菌的acrB基因序列比较分析,序列同源性在98%~99%之间,说明志贺菌主动外排基因acrB在碱基序列和编码的氨基酸序列上均与大肠杆菌有很高的同源性,它可能是志贺菌引起多重耐药的主要原因.     

Physical mapping of a translocation breakpoint in neurofibromatosis

The gene for von Recklinghausen neurofibromatosis (NF1), one of the most common autosomal-dominant disorders of humans, was recently mapped to chromosome 17 by linkage analysis. The identification of two NF1 patients with balanced translocations that involved chromosome 17q11.2 suggests that the disease can arise by gross rearrangement of the NF1 locus, and that the NF1 gene might be identified by cloning the region around these translocation breakpoints. To further define the region of these translocations, a series of chromosome 17 Not I-linking clones has been mapped to proximal 17q and studied by pulsed-field gel electrophoresis. One clone, 17L1 (D17S133), clearly identifies the breakpoint in an NF1 patient with a t(1;17) translocation. A 2.3-megabase pulsed-field map of this region was constructed and indicates that the NF1 breakpoint is only 10 to 240 kilobases away from 17L1. This finding prepares the way for the cloning of NF1.     

肝素黄杆菌2-O-sulfatase基因的克隆与表达

[目的]研究肝素黄杆菌2-O-sulfatase基因的克隆与表达。[方法]以肝素黄肝菌为模板,通过PCR从肝素黄杆菌基因组DNA中扩增2-O-sulfatase的基因,测序正确后插入到表达质粒PET-28a（＋）上构建表达载体,重组质粒转化E.coil BL21（DE3）进行蛋白质表达。[结果]成功地将PCR扩增得到的测序正确的2-O-sulfatase基因构建入PET-28a（＋）载体上,重组质粒转入E.coil BL21（DE3）后,表达产物经SDS-PAGE凝胶电泳鉴定得到目的蛋白。[结论]克隆并成功表达了黄杆菌2-O-sulfatase基因,为分析肝素多糖分子及其降解产物结构奠定了基础。     

单体红色荧光蛋白基因DsRed2的克隆及其原核表达

从原始质粒p DsRed2-1中分离红色荧光蛋白基因DsRed2、构建原核表达载体p GEX4T1-DsRed2,进行了原核表达。结果表明:目标DNA序列含有由678 bp构成的开放阅读框(ORF),编码由225个氨基酸构成的蛋白(红色荧光蛋白,简称RFP2)。与参考序列相比,目标DNA序列在其ORF内存在一个单碱基的同义突变,所编码的目的蛋白氨基酸序列不变。DsRed2基因在常用的表达菌株BL21(DE3)和克隆菌株DH5α中都能够表达出目的蛋白RFP2,使菌落呈现红色。在BL21(DE3)中,在1~5 h内,随诱导时间的延长,RFP2的表达量迅速增加,此后增加不明显。在原核细胞中表达出的RFP2,大多以难溶性包涵体形式存在,仅少量溶于细胞质中,但都能正常显示出红色。RFP2为单体红色荧光蛋白,且在自然光下即可激发出红色荧光;DsRed2作为报告基因,可以非常简单、方便地区分出阳性和假阳性菌落。     

Male-specific antigen: modification of potency by the H-2 locus in mice

Skin grafts from C57BL/10 (B10) male mice survive significantly longer than do B10.BR male skin grafts on (B10 x X B10.BR)F(1) females. This indicates that the H-2 locus influences the potency of the male-specific antigen in mice.     

猪细小病毒NJ-1株VP2基因克隆与抗原性分析

参考Gen Bank公布的NADL-2株序列,设计出1对引物,并利用该引物扩增了猪细小病毒NJ-1株VP2主要抗原基因,将其克隆到pGEM-T Easy载体上,测序获得882 bp核苷酸序列,并推导出其氨基酸序列,共编码294aa,与NADL-2株相应的序列进行比较分析,两者核苷酸同源性为99.2%,氨基酸同源性为99%;应用DNAStar软件对氨基酸的抗原表位进行了预测,共有9个抗原表位,分别在氨基酸N端的第34-40,62-70,88-92,137-157,167-181,189-200,206-219,258-272和280-294区段,此序列具有较好的免疫原性.     

Analysis on Cloning and Expression of Promoter of Flowering Time GmFT2a in Soybean

Soybean (Glycine max) is short-day (SD) plant. Flowering time is a key agronomic trait that determines the transition from vegetative to reproductive growth. Th...