title: Polymerase Θ is a key driver of genome evolution and of CRISPR/Cas9-mediated mutagenesis.
abstract: Cells are protected from toxic DNA double-stranded breaks (DSBs) by a number of DNA repair mechanisms, including some that are intrinsically error prone, thus resulting in mutations. To what extent these mechanisms contribute to evolutionary diversification remains unknown. Here, we demonstrate that the A-family polymerase theta (POLQ) is a major driver of inheritable genomic alterations in Caenorhabditis elegans. Unlike somatic cells, which use non-homologous end joining (NHEJ) to repair DNA transposon-induced DSBs, germ cells use polymerase theta-mediated end joining, a conceptually simple repair mechanism requiring only one nucleotide as a template for repair. Also CRISPR/Cas9-induced genomic changes are exclusively generated through polymerase theta-mediated end joining, refuting a previously assumed requirement for NHEJ in their formation. Finally, through whole-genome sequencing of propagated populations, we show that only POLQ-proficient animals accumulate genomic scars that are abundantly present in genomes of wild C. elegans, pointing towards POLQ as a major driver of genome diversification.
authors.affiliation: Department of Human Genetics, Leiden University Medical Center, PO Box 9600, 2300 RC, Leiden, The Netherlands.
authors.forename: Robin
authors.initials: R
authors.lastname: van Schendel
authors.affiliation: Department of Human Genetics, Leiden University Medical Center, PO Box 9600, 2300 RC, Leiden, The Netherlands.
authors.forename: Sophie F
authors.initials: SF
authors.lastname: Roerink
authors.affiliation: Department of Biology, Division of Developmental Biology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
authors.forename: Vincent
authors.initials: V
authors.lastname: Portegijs
authors.affiliation: Department of Biology, Division of Developmental Biology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
authors.forename: Sander
authors.initials: S
authors.lastname: van den Heuvel
authors.affiliation: Department of Human Genetics, Leiden University Medical Center, PO Box 9600, 2300 RC, Leiden, The Netherlands.
authors.forename: Marcel
authors.initials: M
authors.lastname: Tijsterman
mesh_terms: D000818:Animals; D064113:CRISPR-Cas Systems; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000235:genetics*; D053903:DNA Breaks, Double-Stranded; D059766:DNA End-Joining Repair; D004260:DNA Repair; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D019143:Evolution, Molecular; D049751:Genome, Helminth / Q000235:genetics*; D005854:Germ Cells / Q000378:metabolism*; D018095:Germ-Line Mutation / Q000235:genetics*; D016296:Mutagenesis; D009154:Mutation; D000097462:DNA Polymerase theta
chemical_list: D029742:Caenorhabditis elegans Proteins; D004259:DNA-Directed DNA Polymerase; D000097462:DNA Polymerase theta