Fig. 1

USC mitochondria resemble oocyte morphologically with higher quantities, MMP and lower ROS less affected by age. A Mitochondrial morphology of different types of human primary GC and MSCs under transmission electron microscopy (TEM). Arrows indicate mitochondria with abnormal cristae. Scale bars, 500 nm. B Percentage of round, sausage-like, elongated shape mitochondria among different cell types. C Percentage of mitochondria with normal cristae among different cell types. D Absolute quantification of mtDNA copy number by RT-PCR. E Mitochondrial membrane potential (MMP, indicated by TMRM) and cytosolic reactive oxygen species (ROS, indicated by DCF) were observed under 3D confocal microscope. Scale bars, 10 μm. F The relative abundance of average MMP fluorescence intensity was quantified. G The relative abundance of average ROS fluorescence intensity was quantified. Data are shown as means ± SEM. Each scatter represents an independent biological individual. One-way ANOVA, LSD test. *P < 0.05, **P < 0.01