Cells were harvested using TRIzol reagent (Invitrogen, 10296028), and total RNA was isolated according to the manufacturer's protocol. The RNA-seq libraries were generated from a total of 50 oocytes and 50,000 GCs. After pre-amplification and AMPure XP beads purification, cDNAs were subject to RNA library prep kit for Illumina (NEB, E7770). All libraries were sequenced on the Novaseq 6000 platform to at least a depth of 1.5×107 reads.