Figure 1

Preimplantation development and metabolic profile of mouse embryos harbouring bovine mtDNAs. (A) Developmental arrest in the mouse embryos harbouring bovine mtDNAs (mtB-M embryos (n = 97); orange). Note that proportions of surviving embryos in mtB-M embryos from the 4-cell (4C) stage were significantly reduced compared to IVF embryos (n = 128; blue) and mtM-M embryos (mouse embryos with mitochondria derived from other mouse embryos (n = 59); grey). Data were analyzed after arcsine transformation. *p < 0.05 and **p < 0.01. (B, C) Production levels of cellular reactive oxygen species (ROS) at the 4C stage and 8C stage. IVF (4C: n = 23, 8C: n = 23), mtM-M (n = 4, 12), and mtB-M (n = 7, 18). The ROS level in the mtB-M embryos at the 4C stage was elevated compared to that in the IVF embryos (***p < 0.001). Bar graph shows mean ± standard error of the mean (S.E.M.). (D) Relative expression of mitochondrial respiratory chain (MRC) complex-related genes at the 4C stage. Ndufa3 for MRC complex I [IVF (n = 6) vs. mtB-M (n = 7)], Sdhd for MRC complex II (n = 4 vs. n = 4), Uqcr10 for MRC complex III (n = 6 vs. n = 7), Cox6b1 for MRC complex IV (n = 6 vs. n = 7), and Atp5h for MRC complex V (n = 4 vs. n = 4). Each value was normalised to H2afz expression. *p < 0.05. (E) The ATP contents (pmol / embryo) in IVF and mtB-M embryos. More than 50 embryos were measured for each cell stage, and then, values within mean ± 1 standard deviation were selected. Among them, 28 to 42 embryos were analyzed for each cell stage. The data for all embryos were represented in Fig. S2. *p < 0.05 and **p < 0.01. (F) The PDH activity in IVF (n = 18–33; blue), mtB-M (n = 15–21; orange) embryos, and presumptive 1C stage bovine (n = 9; white) embryos. *p < 0.05, **p < 0.01, and ***p < 0.001.