Mouse endogenous retroviruses can trigger premature transcriptional termination at a distance

Differential methylation at ERV_Slc15a2 reflects its parent of origin. DNA methylation at left (L) 5′ and right (R) 3′ LTRs of ERV_Slc15a2 was assessed using bisulfite sequencing of genomic DNA purified from brains of indicated mouse lineages. (Top, schematic) In amplicon L, primers DES2652 and DES4883 yielded a 272-nt genomic DNA fragment to assess the methylation status of 11 CpG dinucleotides (circles) presented for multiple cloned alleles (horizontal lines). In amplicon R, primers DES4881 and DES2649 yielded a 304-nt fragment to assess eight CpGs. (Filled circles) Methylated cytosine; (open) unmethylated. (Upper left corner of each panel) Percentages of cytosines that are methylated.