Contribution of Spontaneous Mutations to Quantitative and Molecular Variation at the Highly Repetitive rDNA Locus in Yeast.

ABSTRACT: The ribosomal DNA array in Saccharomyces cerevisiae consists of many tandem repeats whose copy number is believed to be functionally important but highly labile. Regulatory mechanisms have evolved to maintain copy number by directed mutation, but how spontaneous variation at this locus is generated and selected has not been well characterized. We applied a mutation accumulation approach to quantify the impacts of mutation and selection on this unique genomic feature across hundreds of mutant strains. We find that mutational variance for this trait is relatively high, and that unselected mutations elsewhere in the genome can disrupt copy number maintenance. In consequence, copy number generally declines gradually, consistent with a previously proposed model of rDNA maintenance where a downw

SUBMITTER: Sharp NP 

PROVIDER: S-EPMC10581546 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature