RRC ID 326
著者 Kawahara Y, Matsuo T, Nozawa M, Shin-I T, Kohara Y, Aigaki T.
タイトル Comparative sequence analysis of a gene-dense region among closely related species of Drosophila melanogaster.
ジャーナル Genes Genet Syst
Abstract Comparative sequence analysis among closely related species is essential for investigating the evolution of non-coding sequences, which evolve more rapidly than protein-coding sequences. We sequenced the cytogenetic map 56F10-16, a gene-dense region of D. simulans and D. sechellia, closely related species to D. melanogaster. About 57 kb of the genomic sequences containing 19 genes were annotated from each species according to the corresponding region of the D. melanogaster genome. The order and orientation of genes were perfectly conserved among the three species, and no transposable elements were found. The rate of nucleotide substitutions in the non-coding sequences was lower than that at the fourfold-degenerate sites, implying functional constraints in the non-coding regions. The sequence information from three closely related species, allowed us to estimate the insertions and the deletions that may have occurred in the lineages of D. simulans and D. sechellia using the D. melanogaster sequence as an outgroup. The number of deletions was twice that of insertions for the introns of D. simulans. More remarkably, the deletion outnumbered insertions by 7.5 times for the intergenic sequences of D. sechellia. These results suggest that the non-coding sequences have been shortened by deletion biases. However, the deletion bias was lower than that previously estimated for pseudogenes, suggesting that the non-coding sequences are already rich in functional elements, possibly involved in the regulation of gene expression including transcription and pre-mRNA processing. These features of non-coding sequences may be common to other gene-dense regions contributing to the compactness of the Drosophila genome.
巻・号 79(6)
ページ 351-9
公開日 2004-12-1
DOI 10.1266/ggs.79.351
PII JST.JSTAGE/ggs/79.351
PMID 15729003
MeSH Animals Chromosome Mapping Classification* DNA Transposable Elements Drosophila / classification* Drosophila / genetics* Evolution, Molecular* Frameshift Mutation Introns Pseudogenes RNA, Untranslated Sequence Analysis, DNA*
IF 0.917
引用数 4
WOS 分野 GENETICS & HEREDITY BIOCHEMISTRY & MOLECULAR BIOLOGY
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