Characterization of the flanking regions of the S-RNase genes of Japanese pear (Pyrus serotina) and apple (Malus x domestica)

Koichiro Ushijima, Hidenori Sassa, Hisashi Hirano

Research output: Contribution to journalArticlepeer-review

34 Citations (Scopus)


Genomic sequences of the self-incompatibility genes, the S-RNase genes, from two rosaceous species, Japanese pear and apple, were characterized. Genomic Southern blot and sequencing of a 4.5-kb genomic clone showed that the S4-RNase gene of Japanese pear is surrounded by repetitive sequences as in the case of the S-RNase genes of solanaceous species. The flanking regions of the S2- and S(f)-RNase genes of apple were also cloned and sequenced. The 5' flanking regions of the three alleles bore no similarity with those of the solanaceous S-RNase genes, although the position and sequence of the putative TATA box were conserved. The putative promoter regions of the Japanese pear S4- and apple S(f)-RNase genes shared a stretch of about 200 bp with 80% sequence identity. However, this sequence was not present in the S2-RNase gene of apple, and thus it may reflect a close relationship between the S4- and S(f)-RNase genes rather than a cis-element important in regulating gene expression. Despite the uniform pattern of expression of the rosaceous S-RNase genes, sequence motifs conserved in the 5' flanking regions of the three alleles were not found, implying that the cis-element controlling pistil specific gene expression also locates at the intragenic region or upstream of the analyzed promoter region.

Original languageEnglish
Pages (from-to)159-167
Number of pages9
Issue number1
Publication statusPublished - Apr 28 1998
Externally publishedYes


  • Genomic sequence
  • Promoter
  • Repetitive sequence
  • Ribonuclease
  • Rosaceae
  • Self-incompatibility

ASJC Scopus subject areas

  • Genetics


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