Therapeutic potential of umbilical cord-derived mesenchymal stem cells in ameliorating ovarian aging: Insights from single-cell analysis

Figure 4 Umbilical cord-derived mesenchymal stem cell transplantation improves the meiotic apparatus and reduces aneuploidy tendency in oocytes from aged mice. A: Representative immunofluorescence images of meiotic spindles (green, α-tubulin) and chromosomes (blue, DAPI) in metaphase II (MII) oocytes. Scale bar = 20 μm; B: Quantitative analysis of the percentage of oocytes with normal spindle morphology. Umbilical cord-derived mesenchymal stem cell transplantation (A-MSC) significantly rescued the age-related decline in normal spindle formation; C: Representative images of chromosome spreads from MII oocytes, showing a normal euploid count (20 chromosomes) and an abnormal aneuploid count (21 chromosomes). Scale bar = 20 μm; D: Quantitative analysis of the percentage of oocytes with a normal chromosome count (20); E: Bar chart showing the percentages of aneuploid oocytes and oocytes with copy number variations across the different groups. Data are presented as mean ± SEM. ^aP < 0.05, ^bP < 0.01, ^cP < 0.001. Y-CON: Young control; A-CON: Aged control; A-MSC: Umbilical cord-derived mesenchymal stem cell transplantation; CNV: Copy number variation.