Plant Molecular Biology

, Volume 45, Issue 1, pp 31–39

Surveying CpG methylation at 5′-CCGG in the genomes of rice cultivars

  • Ikuo Ashikawa

DOI: 10.1023/A:1006457321781

Cite this article as:
Ashikawa, I. Plant Mol Biol (2001) 45: 31. doi:10.1023/A:1006457321781


We investigated the CpG methylation status of the sequence CCGG in the rice genome by using methylation-sensitive AFLP and subsequent Southern analyses with the isolated AFLP fragments as probes. CpGs located in single- or low-copy-sequence regions could be grouped into two classes on the basis of their methylation status: methylation status at the class 1 CpG sites was conserved among genetically diverse rice cultivars, whereas cultivar-specific differential methylation was frequently detected among the cultivars at the class 2 CpG sites. The frequency of occurrence of methylation polymorphism between a pair of cultivars was not related to the genetic distance between the two. Through mapping, five class 2 CpG sites were localized on different chromosomes and were not clustered together in the genome. Segregation analysis of the cultivar-specific methylations with their target sites indicated that the differential methylation was stably inherited in a Mendelian fashion over 6 generations, although alterations in the methylation status at the class 2 CpG sites were observed with a low frequency.

AFLP cytosine methylation rice genome 

Copyright information

© Kluwer Academic Publishers 2001

Authors and Affiliations

  • Ikuo Ashikawa
    • 1
  1. 1.Hokuriku National Agricultural Experiment StationInada, Joetsu, NiigataJapan

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