RT Journal Article SR Electronic T1 A novel process of successive inter-strand template switches explains complex mutations and creates hair-pins JF bioRxiv FD Cold Spring Harbor Laboratory SP 038380 DO 10.1101/038380 A1 Ari Löytynoja A1 Nick Goldman YR 2016 UL http://biorxiv.org/content/early/2016/02/01/038380.abstract AB Resequencing efforts are uncovering the extent of genetic variation in humans and provide data to study the evolutionary processes shaping our genome. One recurring puzzle has been the abundance of complex mutations comprising multiple near-by base substitutions or insertion-deletions. We devised a generalized mutation model to study the role of template switch events in the origin of mutation clusters. Applied to the human genome, the novel model finds strong evidence for inter-strand template switch events and identifies new types of mutations that create short inversions, some flanked by a pair of inverted repeats. This new, local template switch process can create complex mutation patterns, including secondary structures, and explains apparent high frequencies of compensatory substitutions and multi-nucleotide mutations without invoking positive selection. Many of these complex mutations are polymorphic in humans but their detection with current sequencing methodologies is difficult.