Gene organization in rice revealed by full-length cDNA mapping and gene expression analysis through microarray.
Rice (Oryza sativa L.) is a model organism for the functional genomics of monocotyledonous plants since the genome size is considerably smaller than those of other monocotyledonous plants. Although highly accurate genome sequences of indica and japonica rice are available, additional resources such as full-length complementary DNA (FL-cDNA) sequences are also indispensable for comprehensive analyses of gene structure and function. We cross-referenced 28.5K individual loci in the rice genome defined by mapping of 578K FL-cDNA clones with the 56K loci predicted in the TIGR genome assembly. Based on the annotation status and the presence of corresponding cDNA clones, genes were classified into 23K annotated expressed (AE) genes, 33K annotated non-expressed (ANE) genes, and 5.5K non-annotated expressed (NAE) genes. We developed a 60mer oligo-array for analysis of gene expression from each locus. Analysis of gene structures and expression levels revealed that the general features of gene structure and expression of NAE and ANE genes were considerably different from those of AE genes. The results also suggested that the cloning efficiency of rice FL-cDNA is associated with the transcription activity of the corresponding genetic locus, although other factors may also have an effect. Comparison of the coverage of FL-cDNA among gene families suggested that FL-cDNA from genes encoding rice- or eukaryote-specific domains, and those involved in regulatory functions were difficult to produce in bacterial cells. Collectively, these results indicate that rice genes can be divided into distinct groups based on transcription activity and gene structure, and that the coverage bias of FL-cDNA clones exists due to the incompatibility of certain eukaryotic genes in bacteria.
Division of Genome and Biodiversity Research, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
Kouji
K
Satoh
Koji
K
Doi
Toshifumi
T
Nagata
Naoki
N
Kishimoto
Kohji
K
Suzuki
Yasuhiro
Y
Otomo
Jun
J
Kawai
Mari
M
Nakamura
Tomoko
T
Hirozane-Kishikawa
Saeko
S
Kanagawa
Takahiro
T
Arakawa
Juri
J
Takahashi-Iida
Mitsuyoshi
M
Murata
Noriko
N
Ninomiya
Daisuke
D
Sasaki
Shiro
S
Fukuda
Michihira
M
Tagami
Harumi
H
Yamagata
Kanako
K
Kurita
Kozue
K
Kamiya
Mayu
M
Yamamoto
Ari
A
Kikuta
Takahito
T
Bito
Nahoko
N
Fujitsuka
Kazue
K
Ito
Hiroyuki
H
Kanamori
Il-Ryong
IR
Choi
Yoshiaki
Y
Nagamura
Takashi
T
Matsumoto
Kazuo
K
Murakami
Ken-ichi
K
Matsubara
Piero
P
Carninci
Yoshihide
Y
Hayashizaki
Shoshi
S
Kikuchi
D002874:Chromosome Mapping; D018076:DNA, Complementary / Q000235:genetics*; D018744:DNA, Plant / Q000235:genetics*; D005091:Exons; D020869:Gene Expression Profiling; D007438:Introns; D012275:Oryza / Q000235:genetics*
D018076:DNA, Complementary; D018744:DNA, Plant