Fig. 4

Discovery of normal controls vs. normally methylated oligozoospermic sperm DMRs. (a) Flow chart of the discovery of 19 DMRs between NC and NMO sperm groups (left) and the distribution of DMRs according to the range of values in normal controls, with DMRs having NC range < 0.3 highlighted in grey (right). (b) Box plots showing for the 19 DMRs the distribution of the methylation values for NC (teal, n = 5), and NMO (purple, n = 6) (Additional file 1: Table S7). (c) Box plots showing for 17 DMRs the distribution of the methylation values obtained by targeted DBS in an independent cohort. VNC, validation normal control samples (teal, n = 20), VNMO, validation normally methylated oligozoospermic samples (purple, n = 20) (Additional file 1: Table S11). Statistical analyses showed no differences between the two groups (Mann-Whitney U test followed by Bonferroni correction for multiple testing; Additional file 1: Table S12). Box plot elements are defined as follows: center line: median; box limits: upper and lower quartiles; whiskers: 1.5× interquartile range; points: outliers