Horse MGMT locus organization and schematic representation of the sodium bisulfite analysis. A) A mere schematic, not in scale, presentation of the 5'UTR of the MGMT genomic locus on chromosome 1 is shown; the shaded box indicates the position of the CpG island with respect to the exon 1 and exon 2. The ATG position is also reported. The dotted line indicates the not defined boundary between Exon 1 and regulative region. B) In the top are summerised the Methprimer predicted CpG island and the position of primers used for nested PCR. In the lower part, circles indicate methylation status: filled circles, methylated CpGs; open circles: unmethylated CpGs. Each row of circles corresponds to one clone. For each sample 73 CpGs were analysed; the column on the left of each sample are referred to the number of indipendent clones sequenced. C, control tissue; S2, sarcoid sample; E, E-Derm cell line; 4b, Sarcoid cell line EqSO4b.