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Updated: Aug 11, 2026

Use of Bisection to Reduce Mitochondrial DNA in the Bovine Oocyte
Published on: July 6, 2022
Mitochondrial DNA deletion in granulosa and cumulus oophorus cells
Carina C W Chan1, Vincent W S Liu, Estella Y L Lau
1Department of Obstetrics and Gynaecology, The University of Hong Kong, Queen Mary Hospital, Hong Kong. cwcchan@graduate.hku.hk
Abstract:
The incidence of the 4,977-bp deletion in mitochondrial DNA (DeltamtDNA4977) in 73 pairs of granulosa and cumulus oophorus cells was studied with polymerase chain reaction (PCR), and was significantly higher in granulosa cells (GC) (67/73, 91%) than in cumulus oophorus cells (17/73, 23.3%), independent of the donors' age. In the cumulus oophorus cells, the oocyte morphology, the ooplasma diameter, and the proportion of oocytes fertilized normally were comparable between those with and without DeltamtDNA4977; whereas the oocyte diameter and the zona thickness were significantly higher in those with DeltamtDNA4977.
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