Linking high GC content to the repair of double strand breaks in prokaryotic genomes

Abstract

Genomic GC content varies widely among microbes for reasons unknown. While mutation bias partially explains this variation, prokaryotes near-universally have a higher GC content than predicted solely by this bias. Debate surrounds the relative importance of the remaining explanations of selection versus biased gene conversion favoring GC alleles. Some environments (e.g. soils) are associated with a high genomic GC content of their inhabitants, which implies that either high GC content is a selective adaptation to particular habitats, or that certain habitats favor increased rates of gene conversion. Here, we report a novel association between the presence of the non-homologous end joining DNA double-strand break repair pathway and GC content; this observation suggests that DNA damage may be a fundamental driver of GC content, leading in part to the many environmental patterns observed to-date. We discuss potential mechanisms accounting for the observed association, and provide preliminary evidence that sites experiencing higher rates of double-strand breaks are under selection for increased GC content relative to the genomic background.

Document Details

Document Type
Pub Defense Publication
Publication Date
Nov 08, 2019
Source ID
10.1371/journal.pgen.1008493

Entities

People

  • Jake L Weissman
  • Philip L F Johnson
  • William F. Fagan

Organizations

  • Division of Graduate Education
  • National Institute of General Medical Sciences
  • United States Army Research Laboratory
  • United States Department of Education

Tags

Fields of Study

  • Biology

Readers

  • Educational Psychology
  • Mathematics or Statistics
  • Molecular and genetic basis of cancer.