a, Mouse m1A peaks have a significantly higher GC content compared to negative peaks. Box limits represent 25th percentile, median and 75th percentile, whiskers represent 2.5 and 97.5 percentiles, and dots indicate outliers. P = 4.4 × 10−175, t-test. b, Motifs identified in 400-nucleotide windows centred on the canonical AUG start codon in genes with m1A peaks in this window in mouse liver. c, d, GC content (c) and MFEden (d) of 5′ UTRs of methylated (m1A), unmethylated (Non-m1A) and all genes. Box limits represent 25th percentile, median and 75th percentile, whiskers represent 2.5 and 97.5 percentiles. P values are indicted, t-test. e, f, A sliding window profile of mean GC content (e) and mean ΔG (f) in a 300-nucleotide window centred on the canonical AUG start codon in methylated (m1A) genes compared to all other genes in mouse liver. P values are indicated, Kolmogorov–Smirnov test and t-test. g, Representative plots of human-mouse orthologous genes with conserved m1A peaks. Plot format as in Fig. 2a.