library_construction_protocol: FACS-sorted cells were isolated from P1 ovaries or P3 testis and pooled as one replicate. Samples were lysed in 50 μl of lysis buffer (10 mM Tris–HCl (pH 7.4), 10 mM NaCl, 3 mM MgCl2, and 0.1% NP-40, 0.1% Tween-20, and 0.01% Digitonin) on ice for 10 min. Immediately after lysis, nuclei were spun at 500 × g for 10 min at 4 °C to remove the supernatant. Nuclei were then incubated 10 μl of transposition mix (0.5 µl homemade Tn5 transposase, 5 µl 2× TD buffer (10 mM Tris–HCl (pH 7.6), 10 mM MgCl2, and 20% Dimethyl Formamide), 3.3 µl PBS, 0.1 μl 1% digitonin, 0.1 μl 10% Tween-20, and 1 μl water) at 37 °C for 30 min in a thermomixer with shaking at 500 rpm. the transposed DNA was purified with a MinElute kit (Qiagen). DNA libraries were prepared through the omni-ATAC method (PMID: 28846090)