Inherent instability of simple DNA repeats shapes an evolutionarily stable distribution of repeat lengths.

ABSTRACT: Using the Telomere-to-Telomere reference, we assemble the distribution of simple tandem repeat lengths present in the human genome. Analyzing over three hundred mammalian genomes, we find remarkable consistency in the shape of the distribution across evolutionary epochs. All observed genomes harbor an excess of long repeats, which are potentially prone to developing into repeat expansion disorders. We measure mutation rates for repeat length instability, quantitatively model the per-generation action of mutations, and observe the corresponding long-term behavior shaping the repeat tract length distribution. We find that short repetitive sequences appear to be a straightforward consequence of random substitution. Evolving largely independently, longer repeats (above roughly 10 nt) emerge an

SUBMITTER: McGinty RJ 

PROVIDER: S-EPMC12769509 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature