Methylation profiling of human gametes, embryos and tissues.

<p>(<b>A</b>) Heatmap of all 25 CpG dinucleotide tiles with maternal (left) and paternal (right) germline-derived methylation maintaining an intermediate state in blastocysts and arranged in descending order according to their placenta methylation profile. Tiles were partitioned according to their hypo- (<20%), hyper- (>80%) or intermediate (>20%, <80%) methylation. Genomic features are included as separate heatmaps. (<b>B</b>) Violin plots classified as the % repetitive sequences per 20 CpG dinucleotide tile for the paternally methylated, maternally methylated and known imprinted DMRs. The numbers in red represent the tiles with unique sequences (defined as >25% repeats). (<b>C</b>) Two novel maternally methylated ubiquitous DMRs associated with the <i>SVOPL</i> and <i>FANCC</i> genes exhibit promoters that are unmethylated in sperm, hypermethylated in oocytes and intermediately methylated in blastocysts, placenta and somatic tissue in methyl-seq datasets. The vertical black lines in the methyl-seq tracks represent the mean methylation value for individual CpG dinucleotides. Green boxes highlight the position of the gDMRs. (<b>D</b>) Bisulphite PCR and subcloning was used for confirmation. Each circle represents a single CpG dinucleotide on a DNA strand. (•) Methylated cytosine, (o) unmethylated cytosine. Each row corresponds to an individual cloned sequence. If heterozygous for a SNP, the parental-origin of methylation is indicated. For clarity only the first 10 CpG dinucleotides are shown. (E) Allelic RT-PCR for <i>SVOPL</i> reveals transcription from the maternal allele in placenta and monoallelic expression in brain and leukocytes.