Research associate, Institute of Community Medicine, University of Tsukuba, Ibaraki,
Professor, Institute of Community Medicine, University of Tsukuba, Ibaraki,
Associate professor, Faculty of Science, The University of Tokyo, Tokyo,
(Received 2 December 1989; accepted 26 January 1990)
The effects of endogenous 5-methylcytosines on deoxyribonucleic acid (DNA) fingerprints were studied. Analysis with methylation-sensitive restriction endonuclease Sau3AI and its methylation-insensitive isoschizomer MboI showed some differences in the patterns generated as a result of 5-methylcytosines at the recognition sites. Moreover, a few bands of sperm DNA did not match those of blood DNA from the same individual, a phenomenon only observed in the digests of methylation-sensitive endonucleases. These findings indicate the unsuitability of methylation-sensitive restriction endonucleases for DNA fingerprinting and other forms of DNA typing, because of the tissue-specific status of the methylation.
Paper ID: JFS12961J