Maternal obesity alters the DNA methylation of oocytes.
(A) Methylation levels of 5mC and 5hmC in oocytes (n>30). 5mC, 5- methylcytosine; 5hmC, 5-hydroxymethylcytosine; DAPI, chromatin.
(B, C) Relative fluorescence intensity of 5mC and 5hmC in GV oocytes.
(D) Genomic methylation level of MII oocytes examined by single-cell whole genome bisulfite sequencing. The control group (CD) has two replicates, and the obesity group (HFD) has three replicates.
(E) Average genomic CG methylation level in MII oocytes. CD, control group; HFD, obesity group; ** means p value < 0.01.
(F) CG methylation levels at different regions in MII oocytes. CGI, CpG island; utr5, 5’ untranslated region; utr3, 3’ untranslated region; repeat, repeat sequence.
(G) Total differentially methylated regions (DMRs) in oocytes of control and obesity groups. Hyper-DMRs, hypermethylated DMRs; hypo-DMRs, hypomethylated DMRs.
(H) Distribution of DMRs on chromosomes in MII oocytes. Outside-to-in: chromosomes, hyper-DMRs, TEs (transcription end regions), and gene, hypo-DMRs.
(I) KEGG pathway enrichment of genes with DMRs at the promoter regions, and the top 20 pathways are presented.
(J) Schedule of breeding. Female C57BL/6 mice fed with normal (CD) or high-fat diet (HFD) for 12 weeks were marked as F0. F1 was produced by F0 mated with normal males, respectively, and marked as CF1 and HF1; F2 was produced by female F1 mated with normal males and marked as CF2 and HF2, respectively.