Biomaterial Database

Effects of cytosine methylation at restriction sites on deoxyribonucleic acid (DNA) typing. 1990

K Washio, and S Ueda, and S Misawa

Department of Legal Medicine, University of Tsukuba, Ibaraki, Japan.

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.

UI	MeSH Term	Description	Entries
D008745	Methylation	Addition of methyl groups. In histo-chemistry methylation is used to esterify carboxyl groups and remove sulfate groups by treating tissue sections with hot methanol in the presence of hydrochloric acid. (From Stedman, 25th ed)	Methylations
D011237	Predictive Value of Tests	In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.	Negative Predictive Value,Positive Predictive Value,Predictive Value Of Test,Predictive Values Of Tests,Negative Predictive Values,Positive Predictive Values,Predictive Value, Negative,Predictive Value, Positive
D012150	Polymorphism, Restriction Fragment Length	Variation occurring within a species in the presence or length of DNA fragment generated by a specific endonuclease at a specific site in the genome. Such variations are generated by mutations that create or abolish recognition sites for these enzymes or change the length of the fragment.	RFLP,Restriction Fragment Length Polymorphism,RFLPs,Restriction Fragment Length Polymorphisms
D003596	Cytosine	A pyrimidine base that is a fundamental unit of nucleic acids.
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D015139	Blotting, Southern	A method (first developed by E.M. Southern) for detection of DNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.	Southern Blotting,Blot, Southern,Southern Blot
D016172	DNA Fingerprinting	A technique for identifying individuals of a species that is based on the uniqueness of their DNA sequence. Uniqueness is determined by identifying which combination of allelic variations occur in the individual at a statistically relevant number of different loci. In forensic studies, RESTRICTION FRAGMENT LENGTH POLYMORPHISM of multiple, highly polymorphic VNTR LOCI or MICROSATELLITE REPEAT loci are analyzed. The number of loci used for the profile depends on the ALLELE FREQUENCY in the population.	DNA Fingerprints,DNA Profiling,DNA Typing,Genetic Fingerprinting,DNA Fingerprint,DNA Fingerprintings,DNA Profilings,DNA Typings,Fingerprint, DNA,Fingerprinting, DNA,Fingerprinting, Genetic,Fingerprintings, DNA,Fingerprintings, Genetic,Fingerprints, DNA,Genetic Fingerprintings,Profiling, DNA,Typing, DNA,Typings, DNA
D044503	5-Methylcytosine	A methylated nucleotide base found in eukaryotic DNA. In ANIMALS, the DNA METHYLATION of CYTOSINE to form 5-methylcytosine is found primarily in the palindromic sequence CpG. In PLANTS, the methylated sequence is CpNpGp, where N can be any base.	5-Methylcytosine Monohydrochloride,5 Methylcytosine,5 Methylcytosine Monohydrochloride,Monohydrochloride, 5-Methylcytosine