Fig. 6: Single-cell sequencing showed that the oocyte transcriptome of 12-month-old Cd38−/− mice resembled that of WT mice at 2 months of age, and age-related oocyte quality decline was attenuated after the deletion of CD38.
a, Workflow of single-oocyte sequencing by SMART-seq. Oocytes were retrieved from young (2-month-old) and aged (12-month-old) mice together with those from 12-month-old Cd38−/− mice. b, PCA of single-oocyte RNA transcriptomes from young (2-month-old) and aged (12-month-old) WT and Cd38−/− mice (n = 4 oocytes for each group). c, Heat map showing gene expression of oocytes from young and aged WT and Cd38−/− mice. d, Venn diagram showing the overlap between age-related downregulated genes (aged versus young) and upregulated genes after CD38 deletion. GO analysis showed 407 DEGs in enriched pathways. P values were calculated by Fisher’s exact test. e, GSEA showing the enrichment of mitochondrial functions in oocytes from 12-month-old Cd38−/− oocytes. P values were calculated based on Fisher’s exact test. f, Representative images of mitochondrial ROS levels in oocytes detected by MitoSOX staining in 12-month-old WT and Cd38−/− oocytes. Scale bar, 100 μm. g, The fluorescence intensity of ROS signals was measured in oocytes from 12-month-old WT and Cd38−/− mice (n = 11–14 mice for each group). h, Representative images of JC-1-stained MII oocytes from 12-month-old WT and Cd38−/− mice. i, The mitochondrial membrane potential was calculated as the ratio of JC-1 red to JC-1 green signals in oocytes from 12-month-old WT and Cd38−/− mice (n = 7–13 oocytes for each group). j, Representative images of spindle assembly and chromosome alignment in oocytes from 12-month-old WT and Cd38−/− mice. k, Mean abnormal spindle ratios in oocytes from 12-month-old WT and Cd38−/− mice (n = 3–5 mice for each group). Scale bar, 5 μm. Data are presented as the mean ± s.e.m. P value was determined by the unpaired two-tailed t-test between the two groups.
