Follicular development of fetal gonads under the skin of adult mice
Adult ovarian tissues or biopsies isolated from patients prior to chemotherapy or irradiation can reconstitute ovarian functions when transplanted either in the abdomen or subcutaneously. This approach avoids invasive surgery and potential risks associated with internal procedures. We investigated whether functional ovaries could develop subcutaneously from early E12.5 fetal gonads without entering meiosis in mouse model. Unexpectedly, the subcutaneously transplanted fetal gonads failed to undergo folliculogenesis, showing meiotic deficiencies, DNA repairdefects, and elevated apoptosis. Thes meiotic defects were partly due to variations in temperature and oxygen concentration. However, in vitro culture of the gonads at 37?C allowed completion of meiotic prophase I. After subcutaneous transplantation, the in vitro cultured E12.5 gonads successfully underwent folliculogenesis, restoring endocrine functions. This suggests potential for using pluripotent stem cell technologies to rejuvenate ovarioids from fetal gonad-like cells, enhancing  endocrine recovery and health span. Overall design: This dataset contains single-cell RNA sequencing data from subcutaneous graft and renal capsule graft tissues. The tissues were harvested 4 days post-grafting for analysis of gene expression profiles.