Fig. 1

Sperm samples selection for WGBS and establishment of groups based on MEST and H19 methylation. (a) Schematic representation of the experimental design. (b) Dot plot representing the mean methylation levels of MEST and H19 measured by deep bisulfite sequencing in 40 normal (teal) and 93 oligozoospermic (black) sperm samples. At the margins, two density plots show the distribution of the MEST and H19 mean methylation values in the normal and oligozoospermic cohort of samples (Additional file 1: Table S2). (c) Example of deep bisulfite sequencing results of MEST and H19 in the three groups: normal control (NC), abnormally methylated oligozoospermic (AMO) and normally methylated oligozoospermic (NMO). Each horizontal line of a plot represents a unique sequence read, while each vertical position represents a CpG site (methylated sites in red, unmethylated sites in blue). (d) Mean methylation values for MEST and H19 in the five NC (teal), five AMO (orange) and six NMO (purple) selected for the WGBS