Expression of DNA methyltransferases (DNMT) and TET methylcytosine dioxygenases during specification of PGCs as measured by real-time qRT-PCR. Gene expression in all the stages was normalized to expression in 25-dpf male PGCs (set as 1). Beta-actin (β-actin) was used as an internal control. RQ: Relative quantification. (a): dnmt1, one-way ANOVA showed p < 0.05, Tukey’s multiple comparisons test showed significant differences between 15-dpf and 25-dpf female PGC samples; (b): dnmt3aa, one-way ANOVA showed no significant differences among the examined stages; (c): dnmt3ba, one-way ANOVA showed no significant differences among the examined stages; (d): dnmt3bb.1, one-way ANOVA showed p < 0.05, Tukey’s multiple comparisons test showed significant differences between 10-dpf vs 15-dpf, 25-dpf female and 25-dpf male PGC samples; (e): tet1, one-way ANOVA showed no significant differences among the examined stages; (f): tet2, one-way ANOVA showed p < 0.001, Tukey’s multiple comparisons tests showed significant differences between 10-dpf vs 12-dpf, 15-dpf, 25-dpf female and 25-dpf male PGC samples; (g): tet3, one-way ANOVA showed no significant differences; (h): A relationship between dnmt3ba, tet2 expression and global 5-mC levels. Data represent the mean ± SEM. Asterisk indicates statistical significance (*p < 0.05, **p < 0.01, ***p < 0.001).