• Open Access

A positive role for yeast extrachromosomal rDNA circles?

Extrachromosomal ribosomal DNA circle accumulation during the retrograde response may suppress mitochondrial cheats in yeast through the action of TAR1



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Yeast mitochondria frequently mutate, and some dysfunctional mitochondria out-compete wild-type versions. The retrograde response enables yeast to tolerate dysfunction, but also produces ribosomal DNA circles (ERCs). We propose that ERC accumulation increases expression of the rDNA antisense gene, TAR1, which counteracts spread of respiration-deficient mitochondria in matings with wild-type yeast.