Characteristics of bovine oocytes with different meiotic competence in terms of their mitochondrial status and expression of nuclear-encoded factors

0380415 - ÚŽFG 2013 RIV DE eng J - Článek v odborném periodiku
Machatková, M. - Jeseta, M. - Hulínská, P. - Knitlová, D. - Němcová, Lucie - Kaňka, Jiří
Characteristics of bovine oocytes with different meiotic competence in terms of their mitochondrial status and expression of nuclear-encoded factors.
Reproduction in Domestical Animals. Roč. 47, č. 5 (2012), s. 806-814. ISSN 0936-6768. E-ISSN 1439-0531
Grant CEP: GA MZe QI91A018
Grant ostatní: GA ČR(CZ) GD523/08/H064
Program: GD
Výzkumný záměr: CEZ:AV0Z50450515
Klíčová slova: bovine oocytes * mitochondrial status * nuclear-encoded factors
Kód oboru RIV: GI - Šlechtění a plemenářství hospodářských zvířat
Impakt faktor: 1.392, rok: 2012

The present study was designed to characterize bovine oocytes with different meiotic competence and atresia levels in terms of their mitochondrial status. Oocyte subpopulations were recovered either from medium (MF) or small (SF) follicles and categorized as healthy, light-atretic and mid-atretic according to oocyte morphology. Mitochondrial activity, morphology and distribution, adenosine triphosphate (ATP) content and expression of mitochondrial transcription factor A (TFAM) and nuclear respiratory factor 1 (NRF1) were assessed before (GV) and after (MII) maturation. The data were related to follicular size regardless of or with regard to oocyte atresia. Regardless of atresia, the MF subpopulation showed a significantly higher mitochondrial activity and frequency of oocytes with granulated mitochondria at GV and clustered mitochondria at MII than the SF subpopulation. With regard to atresia, mitochondrial activity decreased from healthy to mid-atretic oocytes in both MF and SF subpopulations at GV, but in the SF subpopulation at MII, the mitochondrial activity and frequency of oocytes with clustered mitochondria were significantly higher in light-atretic than in healthy oocytes. The light-atretic oocytes also produced more ATP than healthy ones in both SF and MF subpopulations. However, a significantly higher relative abundance of mRNA TFAM was found in SF than MF subpopulations at GV, and this difference remained in mid-atretic oocytes at MII. It can be concluded that meiotic competence and atresia level influence mitochondrial status of immature bovine oocytes. After maturation, healthy oocytes from medium follicles and light-atretic oocytes from small follicles were more developed in terms of mitochondrial status than the other oocytes.
Trvalý link: http://hdl.handle.net/11104/0211130