DNA methylation landscapes of human fetal development. Homo sapiens

Here we assessed the genome-scale DNA methylation of 472,703 autosomal CpG sites in 4 tissues (muscle, amnion, pancreas and adrenal glands) on 3 time-points (9, 18 and 22 weeks) using the Illumina 450k array. We identified 52,134 CpG sites with dynamic DNA methylation during fetal development (gain or loss >20% from 9 to 22 weeks), where the period between 9 and 18 weeks was most dynamic. Loss in DNA methylation (25,579 CpGs), displayed clear tissue-specific patterns near genes enriched for a role in tissue-specific processes. Gain in DNA methylation (26,555 CpGs) occurred often near genes involved in (tissue-specific) developmental processes. Overall design: Comparison of DNA methylation of four fetal human tissues on three time points of gestation: 9, 18 and 22 weeks of gestation.