Pairs of ovary from young (0-1 day old) virgin female were dissected in PBS buffer. Ovaries were cross-linked with 1.8% formaldehyde and nuclei were extracted by tissue homogeneization using Dounce with glass pistone (loose 4 times and tight 8 times) in total 10 min incubation at room temperature.Crosslinking was quenched by adding 125mM glycine followed by incubation for 5 min. Crosslinked isolated Nuclei were lysed in presence of 0.5% SDS and chromatin supernatant was sonicated using Bioruptor (18 cycles, 30s ON/30s OFF). H3K4me3-DNA complexes were isolated with antibody. Libraries were synthesized using Diagenode MicroPlex Library Preparation kit v2 Instruction Manual, version v.2 02.15