The association of mitochondrial potential and copy number with pig oocyte maturation and developmental potential.
ATP is critical for oocyte maturation, fertilization, and subsequent embryo development. Both mitochondrial membrane potential and copy number expand during oocyte maturation. In order to differentiate the roles of mitochondrial metabolic activity and mtDNA copy number during oocyte maturation, we used two inhibitors, FCCP (carbonyl cyanide p-(tri-fluromethoxy)phenyl-hydrazone) and ddC (2'3-dideoxycytidine), to deplete the mitochondrial membrane potential (Δφm) and mitochondrial copy number, respectively. FCCP (2000 nM) reduced ATP production by affecting mitochondrial Δφm, decreased the mRNA expression of Bmp15 (bone morphogenetic protein 15), and shortened the poly(A) tails of Bmp15, Gdf9 (growth differentiation factor 9), and Cyclin B1 transcripts. FCCP (200 and 2000 nM) also affected p34(cdc2) kinase activity. By contrast, ddC did not alter ATP production. Instead, ddC significantly decreased mtDNA copy number (P < 0.05). FCCP (200 and 2000 nM) also decreased extrusion of the first polar body, whereas ddC at all concentrations did not affect the ability of immature oocytes to reach metaphase II. Both FCCP (200 and 2000 nM) and ddC (200 and 2000 µM) reduced parthenogenetic blastocyst formation compared with untreated oocytes. However, these inhibitors did not affect total cell number and apoptosis. These findings suggest that mitochondrial metabolic activity is critical for oocyte maturation and that both mitochondrial metabolic activity and replication contribute to the developmental competence of porcine oocytes.
Department of Animal Sciences, Chungbuk National University, Cheongju, 361-763, South Korea.
Seul-Ki
SK
Lee
Ming-Hui
MH
Zhao
Jung-Woo
JW
Kwon
Ying-Hua
YH
Li
Zi-Li
ZL
Lin
Yong-Xun
YX
Jin
Nam-Hyung
NH
Kim
Xiang-Shun
XS
Cui
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D055430:Bone Morphogenetic Protein 15 / Q000235:genetics / Q000378:metabolism; D016203:CDC2 Protein Kinase / Q000235:genetics / Q000378:metabolism; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D056744:Cyclin B1 / Q000235:genetics / Q000378:metabolism; D004272:DNA, Mitochondrial / Q000235:genetics; D047108:Embryonic Development; D005260:Female; D018628:Gene Dosage / Q000235:genetics / Q000502:physiology*; D055429:Growth Differentiation Factor 9 / Q000235:genetics / Q000378:metabolism; D020287:In Situ Nick-End Labeling; D053078:Membrane Potential, Mitochondrial / Q000235:genetics / Q000502:physiology*; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism*; D009865:Oocytes / Q000166:cytology* / Q000378:metabolism; D012313:RNA / Q000737:chemistry / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D013552:Swine / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D016047:Zalcitabine / Q000494:pharmacology
D055430:Bone Morphogenetic Protein 15; D056744:Cyclin B1; D004272:DNA, Mitochondrial; D055429:Growth Differentiation Factor 9; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D012313:RNA; D016047:Zalcitabine; D000255:Adenosine Triphosphate; D016203:CDC2 Protein Kinase