DPPA3 and cyst: Specifically, we analyzed ribosomal RNA-depleted total RNA isolated from oocytes marked by the Stella-GFP transgene at four critical stages of development: embryonic day 18.5 (E18.5), corresponding to oocytes in the MPI stage residing in germline cysts (E18O); postnatal day 1 (P1), representing oocytes undergoing cyst breakdown during POT (P1O); P5 to 6, when oocytes have completed POT and reside in primordial follicles as NGOs; and P6 to 7, when oocytes have initiated growth and reside in primary follicles as GOs during PPT (Fig. 1a).