BMC Genomics 2009, 10:322 http://www.biomedcentral.com/1471-2164/10/322 FAigpuhyrseic5al map of mouse γ-satellite DNA A physical map of mouse γ-satellite DNA. A – gel photo of mouse genomic DNA cleavage with restriction enzymes (dou- ble digestions). Lanes: 4 – intact DNA; 1, 3, 5, 7, 9 – GlaI added; 1, 2 – AcsI added; 5, 6 – FatI added; 7, 8 – BstF5I added; 9, 10 – Bst2UI added; M – DNA marker pUC19/MspI. B-F – physical maps of mouse γ-satellite DNA with indication of experimen- tally obtained DNA fragments and theoretically predicted ones. B – GlaI; C – double digestion with GlaI and AcsI; D – double digestion with GlaI and FatI; E – double digestion with GlaI and BstF5I; F – double digestion with GlaI and Bst2UI. Experimental patterns of mouse DNA hydrolysis and DNA ladders are shown on a left side of each figure. Positions of cleavage sites are shown in brackets at the top. Intact GlaI fragments are shown in black, cleaved GlaI fragments are shown in grey, double diges- tion products are shown in brown. Horizontal dotted lines show a correspondence of predicted fragments (arrows) to those observed on gel photos. from a known one [11] (missed A nucleotides in positions 68 and 188). Vissel and Choo cleaved γ-satellite DNA with MnlI and determined a primary structure of obtained monomers [13]. Earlier Horz and Altenburger [11] studied MnlI digestion of γ-satellite DNA and showed that methylation of CG dinucleotide in position 74 blocks DNA hydrolysis. So, Vissel and Choo isolated only those DNA monomers, which were unmethylated in position 74 in two neigh- bouring MnlI sites. Besides a distinct consensus sequence, a detailed analysis of these monomers alignment (Addi- tional file 2) has revealed a different distribution of CG dinucleotide mutations in several positions of γ-satellite DNA (see Table 2). Page 7 of 10 (page number not for citation purposes)