The genome size evolution of medaka (Oryzias latipes) and fugu (Takifugu rubripes)

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Author(s)

Abstract

Evolution of the genome size in eukaryotes is often affected by changes in the noncoding sequences, for which insertions and deletions (indels) of small nucleotide sequences and amplification of repetitive elements are considered responsible. In this study, we compared the genomic DNA sequences of two kinds of fish, medaka (<i>Oryzias latipes</i>) and fugu (<i>Takifugu rubripes</i>), which show two-fold difference in the genome size (800 Mb vs. 400 Mb). We selected a contiguous DNA sequence of 790 kb from the medaka chromosome LG22 (linkage group 22), and made a precise comparison with the sequence (387 kb) of the corresponding region of <i>Takifugu</i>. The sequence of 178 kb in total was aligned common between two fishes, and the remaining sequences (612 kb for medaka and 209 kb for fugu) were found abundant in various repetitive elements including many types of unclassified low copy repeats, all of which accounted for more than a half (54%) of the genome size difference. Furthermore, we identified a significant difference in the length ratio of the unaligned sequences that locate between the aligned sequences (USBAS), particularly after eliminating known repetitive elements. These USBAS with no repetitive elements (USBAS-nr) located within the intron and intergenic region. These results strongly indicated that amplification of repetitive elements and compilation of indels are major driving forces to facilitate changes in the genome size.<br>

Journal

  • Genes & Genetic Systems

    Genes & Genetic Systems 82(2), 135-144, 2007-04-25

    The Genetics Society of Japan

References:  49

Codes

  • NII Article ID (NAID)
    10024394027
  • NII NACSIS-CAT ID (NCID)
    AA11077421
  • Text Lang
    ENG
  • Article Type
    ART
  • ISSN
    13417568
  • NDL Article ID
    8734738
  • NDL Source Classification
    ZR1(科学技術--生物学)
  • NDL Call No.
    Z53-W539
  • Data Source
    CJP  NDL  J-STAGE 
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