After mincing, embryo samples were incubated with TryLE Express dissociation reagent (Life Technology) at 37 °C for 15 min, swirled every two minutes, and the reaction was quenched with heat inactivated serum. After washing, the dissociated single-cell suspensions were re-suspended in PBS with 0.04% BSA and filtered through a 40 μm cell strainer. After checking the viability and counting, single-cell suspensions of each group were loaded onto the Chromium Controller and cDNA libraries were constructed using the Chromium Single Cell 3' Library & Gel Bead Kit v3 following the manufacturer's protocol (10X Genomics, Inc.).