Fig. 3

TETs bind to full-length, young L1s. a TET1 ChIP-seq data aligned to a full-length L1Tf element, revealing a specific enrichment at the 5′ UTR. b ChIP-qPCR confirms that TET1 and TET2 bind the 5′ UTR of the three active mouse L1 families, with reduced enrichment at the coding region (representative replicate from n = 3). c L1 clades were ordered according to evolutionary age and the proportion of overlapping TET1 peaks from either unique or inclusive mapping (the latter termed ‘ambiguous’ peaks) calculated; TET1 binding is restricted to full-length (>5 kb) young L1s. d TAB-seq data aligned to a L1Tf element reveal 5hmC enrichment at the 5’ UTR. e TAB-seq and BS-seq data analysis at L1Tf copies shows that TET1 binding is associated with higher 5hmC levels and concomitant lower 5mC (***p < 0.001, Wilcoxon test). f Profile of 5fC and 5caC enrichment along a full-length L1Tf; depletion of TDG leads to an accumulation of these modifications at the 5’ UTR. g Alignment of TAB-seq data from human ESCs to an active L1Hs element also shows an enrichment at the 5’ UTR. h Human L1 families were ordered according to evolutionary age and the levels of 5hmC/5mC extracted from TAB-seq and BS-seq data; young elements have higher 5hmC and lower 5mC levels