library_construction_protocol: After MS-222 anesthesia and blood removal via the caudal vein, ovaries were dissected into ice-cold PBS and perfused to minimize residual blood. Oocytes or embryos were carefully microdissected to isolate pure ovarian stroma. Approximately 3 mL of minced stromal tissue was digested in 10 mL Trypsin-EDTA (0.25% trypsin, 0.02% EDTA) with gentle trituration for 4 min at room temperature. Digestion was quenched using Leibovitz's L-15 supplemented with 10% FBS. The cell suspension was filtered through a 40 μm strainer, centrifuged at 400g for 6 min at 4°C, washed once, and resuspended in ice-cold PBS. Cell concentration and viability were assessed using 0.4% trypan blue staining and a hemocytometer. Single-cell gene-expression libraries were prepared using the Chromium Next GEM Single Cell 3′ v3.1 workflow (10x Genomics) according to the manufacturer's instructions. Gel beads carrying unique molecular identifiers (UMIs) and cell barcodes were loaded near saturation. After lysis, polyadenylated RNAs hybridized to bead-bound oligo-dT primers. Emulsions were broken and beads were recovered for reverse transcription. During cDNA synthesis, each molecule was tagged at the 5' end with its UMI and cell barcode. Bead-bound cDNA underwent second-strand synthesis, adaptor ligation, and universal amplification. Libraries were constructed from randomly fragmented whole-transcriptome amplification products. All remaining steps followed the standard 10x Genomics protocol. Libraries were quantified and sequenced on an Illumina NovaSeq X Plus platform with 2x150 bp paired-end reads.