Abstract |
Mitochondrial DNA ( mtDNA) content is thought to remain stable over the preimplantation period of human embryogenesis that is, therefore, suggested to be entirely dependent on ooplasm mtDNA capital. We have explored the impact of two disease-causing mutations [m.3243A>G myopathy, encephalopathy, lactic acidosis and stroke-like syndrome (MELAS) and m.8344A>G myoclonic epilepsy associated with ragged-red fibers ( MERRF)] on mtDNA amounts in human oocytes and day 4-5 preimplantation embryos. The mtDNA amount was stable in MERRF and control materials, whereas gradually increasing from the germinal vesicle of oogenesis to the blastocyst stage of embryogenesis in MELAS cells, MELAS embryos carrying ∼3-fold higher mtDNA amount than control embryos (P = 0.0003). A correlation between mtDNA copy numbers and mutant loads was observed in MELAS embryos (R(2) = 0.42, P < 0.0013), suggestive of a compensation for the respiratory chain defect resulting from high mutation levels. These results suggest that mtDNA can replicate in early embryos and emphasize the need for sufficient amount of wild-type mtDNA to sustain embryonic development in humans.
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Authors | Sophie Monnot, David C Samuels, Laetitia Hesters, Nelly Frydman, Nadine Gigarel, Philippe Burlet, Violaine Kerbrat, Frédéric Lamazou, René Frydman, Alexandra Benachi, Josué Feingold, Agnes Rotig, Arnold Munnich, Jean-Paul Bonnefont, Julie Steffann |
Journal | Human molecular genetics
(Hum Mol Genet)
Vol. 22
Issue 9
Pg. 1867-72
(May 01 2013)
ISSN: 1460-2083 [Electronic] England |
PMID | 23390135
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
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Topics |
- Acidosis, Lactic
(genetics, pathology)
- DNA Copy Number Variations
- DNA, Mitochondrial
(genetics)
- Embryonic Development
(genetics)
- Humans
- MELAS Syndrome
(genetics, pathology)
- MERRF Syndrome
(genetics, pathology)
- Mutation
- Oocytes
(pathology)
- Oogenesis
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