Structural Analysis of Arabidopsis thaliana Chromosome 5. VII. Sequence Features of the Regions of 1,013,767 bp Covered by Sixteen Physically assigned P1 and TAC Clones

Sixteen Pl and TAC clones assigned to Arabidopsis thaliana chromosome5 were sequenced, and their sequence features were analyzedusing various computer programs. The total length of the sequencesdetermined was 1,013,767 bp. Together with the nucleotide sequencesof 109 clones previously reported, the regions of chromosome5 sequenced so far now total 9,072,622 bp, which presumablycovers approximately one-third of the chromosome. A similaritysearch against the reported gene sequences predicted the presenceof a total of 225 protein-coding genes and/or gene segmentsin the newly sequenced regions, indicating an average gene densityof one gene per 4.5 kb. Introns were identified in 72.4% ofthe potential protein genes for which the entire gene structurewas predicted, and the average number per gene and the averagelength of the introns were 3.3 and 163 bp, respectively. Thesesequence features are essentially identical to those in thepreviously reported sequences. The sequence data and gene informationare available on the World Wide Web database KAOS (Kazusa Arabidopsisdata Opening Site) at http://www.kazusa.or.jp/arabi/.     

Structural analysis of Arabidopsis thaliana chromosome 5. X. Sequence features of the regions of 3,076,755 bp covered by sixty P1 and TAC clones.

In our ongoing project to deduce the nucleotide sequence of Arabidopsis thaliana chromosome 5, non-redundant P1 and TAC clones have been sequenced on the basis of the fine physical map, and as of January, 2000, the sequences of 16.6 Mb representing approximately 60% of chromosome 5 have been accumulated and released at our web site. Along with the sequence determination, structural features of the sequenced regions have been analyzed by applying a variety of computer programs, and we already predicted a total of 2697 potential protein coding genes in the 11,166,130 bp regions, which are covered by 159 P1 and TAC clones. In this paper, we describe the structural features of the 3,076,755 bp regions covered by newly analyzed 60 P1 and TAC clones. A total of 715 potential protein coding genes were identified, giving an average density of the genes identified of 1 gene per 4001 bp. Introns were observed in 80% of the genes, and the average number per gene and the average length of the introns were 4.5 and 147 bp, respectively. These sequence features are nearly identical to those in our latest report in which the data were compiled based on a new standard of gene assignment including the computer-predicted hypothetical genes. The regions also contained 12 tRNA genes when searched by similarity to reported tRNA genes and the tRNA scan-SE program. The sequence data and information on the potential genes are available through the World Wide Web database KAOS (Kazusa Arabidopsis data Opening Site) at http://www.kazusa.or.jp/kaos/.     

Structural analysis of Arabidopsis thaliana chromosome 5. IX. Sequence features of the regions of 1,011,550 bp covered by seventeen P1 and TAC clones.

In this series of projects sequencing the entire genome of Arabidopsis thaliana chromosome 5, non-redundant P1 and TAC clones have been sequenced according to the fine physical map, and as of May 7, 1999, the sequences of 16.2 Mb representing approximately 60% of chromosome 5 have been accumulated and released at our web site. In parallel, structural features of the sequenced regions have been analyzed by applying a variety of computer programs, and to date we have predicted a total of 2380 potential protein-coding genes in the 10,154,580 bp regions, which are covered by 142 P1 and TAC clones. In this paper, we newly analyzed the structural features of the 1,011,550 bp regions covered by additional 17 P1 and TAC clones, and predicted 298 protein-coding genes. The average density of the genes identified was 1 gene per 3394 bp. Introns were observed in 67% of the genes, and the average number per gene and the average length of the introns were 3.2 and 159 bp, respectively. The gene density became higher than the value estimated in the previously analyzed regions (1 gene per 4,267 bp), as the data in this paper were compiled based on a new standard of gene assignment including the computer-predicted hypothetical genes. The regions also contained 8 tRNA genes when searched by similarity to reported tRNA genes and the tRNA scan-SE program. The sequence data and information on the potential genes are available on the database KAOS (Kazusa Arabidopsis data Opening Site) at http://www.kazusa.or.jp/arabi/.     

Structural analysis of Arabidopsis thaliana chromosome 5. VIII. Sequence features of the regions of 1,081,958 bp covered by seventeen physically assigned P1 and TAC clones.

A total of 17 Pl and TAC clones each representing an assigned region of chromosome 5 were isolated from P1 and TAC genomic libraries of Arabidopsis thaliana Columbia, and their nucleotide sequences were determined. The length of the clones sequenced in this study summed up to 1,081,958 bp. As we have previously reported the sequence of 9,072,622 bp by analysis of 125 P1 and TAC clones, the total length of the sequences of chromosome 5 determined so far is now 10,154,580 bp. The sequences were subjected to similarity search against protein and EST databases and analysis with computer programs for gene modeling. As a consequence, a total of 253 potential protein-coding genes with known or predicted functions were identified. The positions of exons which do not show apparent similarity to known genes were also assigned using computer programs for exon prediction. The average density of the genes identified in this study was 1 gene per 4277 bp. Introns were observed in 74% of the potential protein genes, and the average number per gene and the average length of the introns were 4.3 and 168 bp, respectively. The sequence data and gene information are available on the World Wide Web database KAOS (Kazusa Arabidopsis data Opening Site) at http://www.kazusa.or.jp/arabi/.     

Structural analysis of Arabidopsis thaliana chromosome 3. I. Sequence features of the regions of 4,504,864 bp covered by sixty P1 and TAC clones.

Based on the physical map of Arabidopsis thaliana chromosome 3 previously constructed with CIC YAC, TAC, P1 and BAC clones (Sato, S. et al., DNA Res., 5, 163-168, 1998), a total of 60 P1 and TAC clones were sequenced, and the sequence features of the resulting 4,504,864 bp regions were analyzed by applying various computer programs for similarity search and gene modeling. As a result, a total of 1054 potential protein-coding genes were identified. The average density of the genes identified was 1 gene per 4066 bp. Introns were observed in 77% of the genes, and the average number per gene and the average length of the introns were 3.9 and 156 bp, respectively. These sequence features are essentially identical to those of chromosome 5 in our previous reports, but the gene density was slightly higher than that observed for chromosomes 2 and 4. The regions also contained 10 tRNA genes when searched by similarity to reported tRNA genes and the tRNA scan-SE program. The sequence data and information on the potential genes are available through the World Wide Web database KAOS (Kazusa Arabidopsis data Opening Site) at http://www.kazusa.or.jp/kaos/.     

Structural analysis of Arabidopsis thaliana chromosome 3. II. Sequence features of the 4,251,695 bp regions covered by 90 P1, TAC and BAC clones.

To deduce the entire sequence of the top arm of the Arabidopsis thaliana chromosome 3, the sequence determination was performed on a total of 90 P1, TAC and BAC clones chosen according to our sequencing strategy. Sequence features of the resulting 4,251,695 bp regions were analyzed with various computer programs for similarity search and gene modeling. As a result, a total of 941 potential protein-coding genes were identified. The average density of the genes identified was 1 gene per 4210 bp. Introns were observed in 73% of the genes, and the average number per gene and the average length of the introns were 3.6 and 159 bp, respectively. These sequence features are essentially identical to those of chromosomes 3 and 5 in our previous reports. The regions also contained 14 tRNA genes when searched by similarity to reported tRNA genes and the tRNA scan-SE program. The sequence data and information on the potential genes are available through the World Wide Web database KAOS (Kazusa Arabidopsis data Opening Site) at http://www.kazusa.or.jp/kaos/.     

Structural analysis of a Lotus japonicus genome. IV. Sequence features and mapping of seventy-three TAC clones which cover the 7.5 mb regions of the genome.

Using the sequence information of expressed sequences tags (ESTs), cDNAs and genes from Lotus japonicus and other legumes, 73 TAC (transformation-competent artificial chromosomes) clones were selected from a genomic library of L. japonicus accession MG-20, and their nucleotide sequences were determined. The length of the DNA sequenced in this study was 7,455,959 bp, and the total length of the DNA regions sequenced so far is 26,167,443 bp together with the nucleotide sequences of 183 TAC clones previously reported. By similarity searches against the sequences in protein and EST databases and prediction by computer programs, a total of 699 potential protein-encoding genes with known or predicted functions, 163 gene segments and 267 pseudogenes were assigned to the newly sequenced regions. Based oil the nucleotide sequences of the clones, simple sequence repeat length polymorphism (SSLP) or derived cleaved amplified polymorphic sequence (dCAPS) markers were generated, and each clone was located onto the linkage map of two accessions of L. japonicus, Gifu B-129 and Miyakojima MG-20. The sequence data, gene information and mapping information are available through the World Wide Web at http://www.kazusa.or.jp/lotus/.     

Structural analysis of a Lotus japonicus genome. III. Sequence features and mapping of sixty-two TAC clones which cover the 6.7 Mb regions of the genome.

A total of sixty-two clones were selected from a TAC (transformation-competent artificial chromosome) genomic library of the Lotus japonicus accession MG-20 based on the sequence information of expressed sequence tags (ESTs), cDNA and gene information, and their nucleotide sequences were determined. The length of the sequenced regions in this study is 6,682,189 bp, and the total length of the regions sequenced so far is 18,711,484 bp together with the nucleotide sequences of 121 TAC clones previously reported. By comparison with the sequences in protein and EST databases and analysis with computer programs for gene modeling, a total of 573 potential protein-coding genes with known or predicted functions, 91 gene segments and 272 pseudogenes were identified in the newly sequenced regions. Each of the sequenced clones was localized onto the linkage map of two accessions of L. japonicus, Gifu B-129 and Miyakojima MG-20, using simple sequence repeat length polymorphism (SSLP) or derived cleaved amplified polymorphic sequence (dCAPS) markers generated based on the nucleotide sequences of the clones. The sequence data, gene information and mapping information are available through the World Wide Web at http://www.kazusa.or.jp/lotus/.     

Structural analysis of a Lotus japonicus genome. V. Sequence features and mapping of sixty-four TAC clones which cover the 6.4 mb regions of the genome.

We determined the nucleotide sequences of 64 TAC (transformation-competent artificial chromosome) clones selected from genomic libraries of Lotus japonicus accession Miyakojima MG-20 based on the sequence information of expressed sequence tags (ESTs), cDNAs, genes and DNA markers from L. japonicus and other legumes. The length of the DNA regions sequenced in this study was 6,370,255 bp, and the total length of the L. japonicus genome sequenced so far is 32,537,698 bp together with the nucleotide sequences of 256 TAC clones previously reported. Five hundred forty-eight potential protein-encoding genes with known or predicted functions, 127 gene segments and 224 pseudogenes were assigned to the newly sequenced regions by computer prediction and similarity searches against the sequences in protein and EST databases. Based on the nucleotide sequences of the clones, simple sequence repeat length polymorphism (SSLP) or derived cleaved amplified polymorphic sequence (dCAPS) markers were generated, and each clone was genetically localized onto the linkage map of two accessions of L. japonicus, MG-20 and Gifu B-129. The sequence data, gene information and mapping information are available through the World Wide Web at http://www.kazusa.or.jp/lotus/.     

Structural analysis of a Lotus japonicus genome. I. Sequence features and mapping of fifty-six TAC clones which cover the 5.4 mb regions of the genome.

A total of 56 TAC clones with an average insert size of 100 kb were isolated from a TAC library of the Lotus japonicus genome based on the expressed sequences tags (ESTs), cDNA and gene information, and their nucleotide sequences were determined according to the shot-gun based strategy. The total length of the sequenced regions is 5,473,195 bp. By comparison with the sequences in protein and EST databases and analysis with computer programs for gene modeling, a total of 605 potential protein-encoding genes with known or predicted functions, 69 gene segments, and 172 pseudogenes were identified. The average density of the genes assigned so far is 1 gene/8120 bp. Introns were identified in approximately 78% of the potential genes. There was an average of 3.8 introns per gene and the average length of the introns was 375 bp. DNA markers were generated based on the nucleotide sequences obtained, and each clone was mapped onto the linkage map using the F2 mapping population derived from a cross of L. japonicus Gifu B-129 and Miyakojima MG-20. The sequence data, gene information and mapping information are available through the World Wide Web at http://www.kazusa.or.jp/lotus/.     

A Physical Map of Arabidopsis thaliana Chromosome 3 Represented by Two Contigs of CIC YAC, P1, TAC and BAC Clones

We have constructed a physical map of Arabidopsis thaliana chromosome3 by ordering the clones from CIC YAC, P1, TAC and BAC librariesusing the sequences of a variety of genetic and EST markersand terminal sequences of clones. The markers used were 112DNA markers, 145 YAC end sequences, and 156 end sequences ofP1, TAC and BAC clones. The entire genome of chromosome 3, exceptfor the centromeric and telomeric regions, was covered by twolarge contigs, 13.6 Mb and 9.2 Mb long. This physical map willfacilitate map-based cloning experiments as well as genome sequencingof chromosome 3. The map and end sequence information are availableon the KAOS (Kazusa Arabidopsis data Opening Site) web siteat http://www.kazusa.or.jp/arabi/.     

Structural analysis of a Lotus japonicus genome. II. Sequence features and mapping of sixty-five TAC clones which cover the 6.5-mb regions of the genome.

Sixty-five TAC (transformation-competent artificial chromosomes) clones were selected from a genomic library of Lotus japonicus accession MG-20 based on the sequence information of expressed sequences tags (ESTs), cDNA and gene information, and their nucleotide sequences were determined. The average insert size of the TAC clone was approximately 100 kb, and the total length of the sequenced regions in this study is 6,556,100 bp. Together with the nucleotide sequences of 56 TAC clones previously reported, the regions sequenced so far total 12,029,295 bp. By comparison with the sequences in protein and EST databases and by analysis with computer programs for gene modeling, a total of 711 potential protein-encoding genes with known or predicted functions, 239 gene segments and 90 pseudogenes were identified in the newly sequenced regions. The average gene density assigned so far was 1 gene/9140 bp. The average length of the assigned genes was 2.6 kb, which is considerably larger than that assigned in the Arabidopsis thaliana genome (1.9 kb for 6451 genes). Introns were identified in approximately 73% of the potential genes, and the average number and length of the introns per gene were 3.4 and 377 bp, respectively. Simple sequence repeat length polymorphism (SSLP) or derived cleaved amplified polymorphic sequence (dCAPS) markers were generated based on the nucleotide sequences of the genomic clones obtained, and each clone was mapped onto the linkage map using the F2 mapping population derived from a cross of two accessions of L. japonicus, Gifu B-129 and Miyakojima MG-20. The sequence data, gene information and mapping information are available through the World Wide Web at http://www.kazusa.or.jp/lotus/.     

Structural analysis and complete physical map of Arabidopsis thaliana chromosome 5 including centromeric and telomeric regions.

Previously, we have reported a fine physical map of Arabidopsis thaliana chromosome 5, except for the centromeric and telomeric regions, by ordering clones from YAC, P1, TAC, and BAC libraries of the genome consisting of the two contigs of upper arm and lower arm, 11.6 M bases and 14.2 M bases, respectively. Here, the remaining centromeric and telomeric regions of chromosome 5 are completely characterized by the ordering of clones and PCR amplifications. Chromosome 5 of Arabidopsis thaliana ecotype Columbia is about 28.4 M bases long. The centromeric region is estimated at about 2 M bases long between two 5S-rDNA clusters. The 180-bp repeat region mainly consists of blocks of 180-bp tandem family and various type retroelements dispersed over a 500-kb region. The telomeric regions of chromosome 5 are characterized by PCR cloning, sequencing and hybridization. The telomere repeats at both ends are about 2.5-kb long and interestingly, telomere-associated repeats (approximately 700 bp) are found near both ends of chromosome 5.     

H5N1亚型高致病性禽流感病毒NS1基因的克隆及其序列分析

目的：克隆H5N1亚型禽流感病毒的NS1基因,并分析其序列特性。方法：通过RT-PCR方法克隆H5N1亚型禽流感病毒NS1基因,并对该基因片段进行测序,将此序列与数据库中不同时间、地点、宿主来源的H5N1亚型流感毒株NS1基因序列进行同源性比较。结果：获得了678bp的NS1全长基因,可编码225个氨基酸;其与毒株A／chicken／Jilin／hq／2003的同源性最高,二者的核酸和氨基酸的同源性分别为99．7％和99．1％。比对分析发现,该毒株NS1基因在第238-252位有15个核苷酸的缺失;进化树分析表明,它与1997年香港流行的H5N1亚型禽流感病毒毒株分别属于2个不同的分支。结论：克隆了一株H5N1亚型禽流感病毒的NS1基因,并初步分析了其序列特性,为进一步研究NS1基因的功能奠定了基础。     

GCR1和GCR2在N-酰基高丝氨酸内酯调节拟南芥根生长中的作用

N-酰基高丝氨酸内酯（AHLs）是革兰氏阴性细菌群体感应的信号分子。培养基中添加1μmol·L-13OC6-HSL和10μmol·L-13OC8-HSL可显著促进野生型拟南芥主根生长,但拟南芥G蛋白偶联受体GCR1和GCR2基因缺失突变体gcr1-1和gcr2-2对AHLs处理不敏感;实时荧光定量PCR分析显示,这2种AHLs的处理可以使拟南芥GCR1和GCR2基因表达量上调2～4倍。结果表明,G蛋白偶联受体GCR1和GCR2可能参与植物感应细菌信号进而做出根生长响应的信号转导。