A Powerhouse Conversion

See allHide authors and affiliations

Science  01 Jun 2007:
Vol. 316, Issue 5829, pp. 1255
DOI: 10.1126/science.316.5829.1255d

Animal cells contain not only their nuclear genome, which is inherited equally from both parents, but they also, within their mitochondria, carry a further, much smaller genome, which is generally maternally inherited. Mitochondrial DNA is thought not to undergo recombination and to represent a relatively stable record of the evolutionary history of a species. By examining duplicated genes within the mitochondria of killifish, Tatarenkov and Avise found evidence of gene conversion within the mitochondria, suggesting that recombination does occur. Sequences from both copies of the control regions of the mitochondrial DNA identified 28 examples where both copies contained the same nucleotide substitution, resulting in an overestimate of genetic distance between individuals on the basis of paralogs, which arise from gene duplications, in comparison to that estimated from orthologs, which represent genes sharing the same evolutionary history. Thus, recombination and gene conversion are ongoing in the mitochondria of killifish and, by extension, probably in other animals as well. LMZ

Proc. R. Soc. London Ser. B 10.1098/rspb.2007.0169 (2007).

Navigate This Article