Fig. 4
Improvement of mitochondrial content and function in embryos after USC mitochondria transfer. A Representative images of early embryo development in the Control and MITO ICSI groups. a Co-injection of single sperm with USC-derived mitochondria during ICSI; b-c Grade IV embryos on day 3 (b) and Grade 6CB blastocysts on day 6 (c) in the Control group; d-f Fertilization and 2PN formation on day 1 (d), Grade I 8-cells embryos on day 3 (e), and Grade 3BC blastocysts on day 5 (f) in the MITO ICSI group. B Mitochondrial content (indicated by Mitotracker green) and cytosolic Ca2+ (indicated by Fluo-4) were observed under confocal microscope. Scale bars, 50 μm. C MMP (indicated by TMRM) and cytosolic ROS (indicated by DCF) were observed under 3D confocal microscope. The relative abundance of average fluorescence intensity or area was quantified. Data are shown as means ± SEM. Each scatter represents an independent biological individual. Unpaired two-tailed Student’s t-test. *P < 0.05, **P < 0.01