title: Construction of a full-length cDNA library from young spikelets of hexaploid wheat and its characterization by large-scale sequencing of expressed sequence tags.
abstract: The polyploid nature of wheat is a key characteristic of the plant. Full-length complementary DNAs (cDNAs) provide essential information that can be used to annotate the genes and provide a functional analysis of these genes and their products. We constructed a full-length cDNA library derived from young spikelets of common wheat, and obtained 24056 expressed sequence tags (ESTs) from both ends of the cDNA clones. These ESTs were grouped into 3605 contigs using the phrap method, representing expressed loci from each of the three genomes. Using BLAST, 3605 contigs were grouped into 1902 gene clusters, showing that loci of the three genomes are not always expressed. A homology search of these gene clusters against a wheat EST database (15964 gene clusters) and a rice full-length cDNA database (21447 gene clusters) revealed that a quarter of the wheat full-length cDNAs were novel. A protein database of Arabidopsis was used to examine the functional classification of these gene clusters. The GC-content in the 5 -UTR region of wheat cDNAs was compared to that of rice. Forty-three genes (3.5% of wheat cDNAs homologous to those of rice) possessed distinct GC-content in the 5 -UTR region, suggesting different breeding behaviors of wheat and rice.
authors.affiliation: Kihara Institute for Biological Research and Graduate School of Integrated Science, Yokohama City University, Maioka-cho 641-12, Totsuka-ku, Yokohama 244-0813, Japan. yogihara@kab.seika.kyoto.jp
authors.forename: Yasunari
authors.initials: Y
authors.lastname: Ogihara
authors.forename: Keiichi
authors.initials: K
authors.lastname: Mochida
authors.forename: Kanako
authors.initials: K
authors.lastname: Kawaura
authors.forename: Koji
authors.initials: K
authors.lastname: Murai
authors.forename: Motoaki
authors.initials: M
authors.lastname: Seki
authors.forename: Asako
authors.initials: A
authors.lastname: Kamiya
authors.forename: Kazuo
authors.initials: K
authors.lastname: Shinozaki
authors.forename: Piero
authors.initials: P
authors.lastname: Carninci
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Hayashizaki
authors.forename: Tadasu
authors.initials: T
authors.lastname: Shin-I
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kohara
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Yamazaki
mesh_terms: D020121:5' Untranslated Regions; D018076:DNA, Complementary; D020224:Expressed Sequence Tags; D005810:Multigene Family; D011123:Polyploidy; D014908:Triticum / Q000235:genetics*
chemical_list: D020121:5' Untranslated Regions; D018076:DNA, Complementary