Fig. 2: Mitochondrial function and dynamics are impaired in Mfn1^−/− oocytes.

a ATP levels were measured in Mfn1^−/− and WT female mice (8-week-old). b mtDNA copy number was determined by qPCR in individual oocytes collected from Mfn1^−/− and WT mice. c Expression of electron transport chain genes was assessed using qRT-PCR in oocytes collected from Mfn1^−/− and WT mice. d ROS levels were measured in Mfn1^−/− and WT oocytes after treatment with H₂O₂. e Fluorescence intensity of Carboxy-H₂DCFDA was used to measure ROS levels. f Expression of mitochondrial unfolded protein response (mtUPR) genes was assessed using qRT-PCR in oocytes collected from Mfn1^−/− and WT mice. g Representative electron microscopic photographs of oocytes from 8-week-old Mfn1^−/− and WT mice ovaries (n = 3 mice assessed in each group). Arrows show mitochondria. h–k Mitochondrial size (h), aspect ratio (mitochondrial length/ width) (i), coverage area ratio (mitochondrial area/cytoplasm area) (j), and number of mitochondrial cristae (k), in Mfn1^−/− oocytes compared to WT. Data presented as mean ± SEM. *p < 0.05, ***p < 0.001, vs. WT using t-test. ATP adenosine triphosphate, Ndufv1 NADH dehydrogenase (ubiquinone) flavoprotein 1, Sdhb succinate dehydrogenase complex iron sulfur subunit B, Uqcrc2 ubiquinol cytochrome c reductase core protein 2, Cox1 cytochrome c oxidase subunit I, Atp5a1 ATP synthase, H + transporting, mitochondrial F1 complex, alpha subunit 1