Showing papers by "Akiko Watanabe published in 2011"

Sequence Analysis of the Genome of an Oil-Bearing Tree, Jatropha curcas L.

Abstract: The whole genome of Jatropha curcas was sequenced, using a combination of the conventional Sanger method and new-generation multiplex sequencing methods. Total length of the non-redundant sequences thus obtained was 285 858 490 bp consisting of 120 586 contigs and 29 831 singlets. They accounted for ∼95% of the gene-containing regions with the average G 1 C content was 34.3%. A total of 40 929 complete and partial structures of protein encoding genes have been deduced. Comparison with genes of other plant species indicated that 1529 (4%) of the putative protein-encoding genes are specific to the Euphorbiaceae family. A high degree of microsynteny was observed with the genome of castor bean and, to a lesser extent, with those of soybean and Arabidopsis thaliana. In parallel with genome sequencing, cDNAs derived from leaf and callus tissues were subjected to pyrosequencing, and a total of 21 225 unigene data have been generated. Polymorphism analysis using microsatellite markers developed from the genomic sequence data obtained was performed with 12 J. curcas lines collected from various parts of the world to estimate their genetic diversity. The genomic sequence and accompanying information presented here are expected to serve as valuable resources for the acceleration of fundamental and applied research with J. curcas, especially in the fields of environment-related research such as biofuel production. Further information on the genomic sequences and DNA markers is available at http://www.kazusa.or.jp/jatropha/.

Complete Genome Sequence of the Soybean Symbiont Bradyrhizobium japonicum Strain USDA6T.

Abstract: The complete nucleotide sequence of the genome of the soybean symbiont Bradyrhizobium japonicum strain USDA6T was determined. The genome of USDA6T is a single circular chromosome of 9,207,384 bp. The genome size is similar to that of the genome of another soybean symbiont, B. japonicum USDA110 (9,105,828 bp). Comparison of the whole-genome sequences of USDA6T and USDA110 showed colinearity of major regions in the two genomes, although a large inversion exists between them. A significantly high level of sequence conservation was detected in three regions on each genome. The gene constitution and nucleotide sequence features in these three regions indicate that they may have been derived from a symbiosis island. An ancestral, large symbiosis island, approximately 860 kb in total size, appears to have been split into these three regions by unknown large-scale genome rearrangements. The two integration events responsible for this appear to have taken place independently, but through comparable mechanisms, in both genomes.

An EST-SSR Linkage Map of Raphanus sativus and Comparative Genomics of the Brassicaceae

Abstract: Raphanus sativus (2n = 2x = 18) is a widely cultivated member of the family Brassicaceae, for which genomic resources are available only to a limited extent in comparison to many other members of the family. To promote more genetic and genomic studies and to enhance breeding programmes of R. sativus, we have prepared genetic resources such as complementary DNA libraries, expressed sequences tags (ESTs), simple sequence repeat (SSR) markers and a genetic linkage map. A total of 26 606 ESTs have been collected from seedlings, roots, leaves, and flowers, and clustered into 10 381 unigenes. Similarities were observed between the expression patterns of transcripts from R. sativus and those from representative members of the genera Arabidopsis and Brassica, indicating their functional relatedness. The EST sequence data were used to design 3800 SSR markers and consequently 630 polymorphic SSR loci and 213 reported marker loci have been mapped onto nine linkage groups, covering 1129.2 cM with an average distance of 1.3 cM between loci. Comparison of the mapped EST-SSR marker positions in R. sativus with the genome sequence of A. thaliana indicated that the Brassicaceae members have evolved from a common ancestor. It appears that genomic fragments corresponding to those of A. thaliana have been doubled and tripled in R. sativus. The genetic map developed here is expected to provide a standard map for the genetics, genomics, and molecular breeding of R. sativus as well as of related species. The resources are available at http://marker.kazusa.or.jp/Daikon.

Survey of the genetic information carried in the genome of Eucalyptus camaldulensis

Abstract: The genetic information in the genome of Eucalyptus camaldulensis was investigated by sequencing the genome and the cDNA using a combination of the conventional Sanger method and next-generation sequencing methods, followed by intensive bioinformatics analyses. The total length of the non-redundant genomic sequences thus obtained was 654,922,307 bp consisting of 81,246 scaffolds and 121,194 singlets. These sequences accounted for approximately 92% of the gene-containing regions with an average G+C content of 33.6%. A total of 77,121 complete and partial structures of protein-encoding genes have been deduced. Comparison of the genes mapped on the KEGG pathways or located in the KOG classification with those in other plant species revealed the characteristics of the E. camaldulensis genome, and it was found that 23 pathways contained enzymes present only in the E. camaldulensis genome. Polymorphism analysis using microsatellite markers developed from the genomic sequence data obtained was performed with six Eucalyptus species collected from various parts of the world to estimate their genetic diversity, and the usefulness of these markers was demonstrated. The genomic sequence and accompanying information presented here are expected to serve as valuable resources for the acceleration of fundamental and applied research with Eucalyptus, especially in the fields of paper production and industrial materials. Further information on the genomic and cDNA sequences and microsatellite markers is available at http://www.kazusa.or.jp/eucaly/.