Female and male gamete mitochondria are distinct and complementary in transcription, structure, and genome function.
Genome Biol Evol
; 5(10): 1969-77, 2013.
Article
in En
| MEDLINE
| ID: mdl-24068653
ABSTRACT
Respiratory electron transport in mitochondria is coupled to ATP synthesis while generating mutagenic oxygen free radicals. Mitochondrial DNA mutation then accumulates with age, and may set a limit to the lifespan of individual, multicellular organisms. Why is this mutation not inherited? Here we demonstrate that female gametes-oocytes-have unusually small and simple mitochondria that are suppressed for DNA transcription, electron transport, and free radical production. By contrast, male gametes-sperm-and somatic cells of both sexes transcribe mitochondrial genes for respiratory electron carriers and produce oxygen free radicals. This germ-line division between mitochondria of sperm and egg is observed in both the vinegar fruitfly and the zebrafish-species spanning a major evolutionary divide within the animal kingdom. We interpret these findings as an evidence that oocyte mitochondria serve primarily as genetic templates, giving rise, irreversibly and in each new generation, to the familiar energy-transducing mitochondria of somatic cells and male gametes. Suppressed mitochondrial metabolism in the female germ line may therefore constitute a mechanism for increasing the fidelity of mitochondrial DNA inheritance.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Oocytes
/
Spermatozoa
/
Transcription, Genetic
/
DNA, Mitochondrial
/
Biological Evolution
Limits:
Animals
Language:
En
Journal:
Genome Biol Evol
Journal subject:
BIOLOGIA
/
BIOLOGIA MOLECULAR
Year:
2013
Document type:
Article
Affiliation country:
United kingdom