[Use of bacterial DNA-methylases for structuro-functional analysis of the eukaryotic genome]

Bacterial DNA-methylases with known recognition sites (RS) were used as probes for structural-and-functional analysis of eukaryotic genome. Adenine and cytosine DNA-methylases recognizing 4 to 6-member unique and degenerative nucleotide sequences having a symmetrical and asymmetrical structure were used for probing. The use of a set of methylases enabled the selection of a probe that was the most sensitive for the given pathology. Thus, severe hypothyrosis was found to be associated with changes in the acceptor capacity of liver DNA in the heterologous++ methylation reaction as could be evidenced from testing by two probes, CCCC and GAATGC. In the cells of chicken liver hepatoma MC29, the acceptor capacity of DNA during GGA methylation appeared to be altered in the greatest degree. DNA-methylases with degenerative SR are weakly specific probes for the study of structural changes (methylation) of the animal genome.