| Summary: | <p>Abstract</p> <p>Background</p> <p>Patterns of mouse DNA hydrolysis with restriction enzymes are coincided with calculated diagrams of genomic DNA digestion <it>in silico</it>, except presence of additional bright bands, which correspond to monomer and dimer of γ-satellite DNA. Only small portion of mouse γ-satellite DNA sequences are presented in databases. Methyl-directed endonuclease GlaI cleaves mouse DNA and may be useful for a detailed study of primary structure and CG dinucleotides methylation in γ-satellite DNA.</p> <p>Results</p> <p>We have constructed a physical map and produced experimental patterns of mouse γ-satellite DNA hydrolysis with unique site-specific methyl-directed endonuclease GlaI and several restriction endonucleases. Fifty two DNA fragments of γ-satellite DNA have been cloned and sequenced. We have not observed any mutations of CG dinucleotide in position 208 of monomeric γ-satellite DNA and confirmed 50% methylation of this CG dinucleoitide. A comparison of consensus sequences of arrayed γ-satellite DNA and small blocks of satellite DNA (140 monomers and less) has shown a higher level of mutations and an absence of conserved CG dinucleotide in last ones. A replacement of CG dinucleotide by CA-dinucleotide in positions 178 and 17 in chromosomes 9 and 3, respectively, has been observed in blocks of monomers.</p> <p>Conclusion</p> <p>Arrayed γ-satellite DNA from mouse has at least one conservative CG-dinucleotide. Consensus sequences of this DNA and γ-satellite DNA in small blocks of monomers are differing. The last one displays a higher level of CG dinucleotides mutations and an absence of conservative CG-dinucleotide. Presence of conservative and half-methylated CG-dinucleotide supports an idea of importance of this CG dinucleotide methylation/demethylation in arrayed γ-satellite DNA functioning.</p>
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