Recombination Interval Used for Molecular Analyses

<div><p>(A) The 3.5-kilobase ectopic recombination interval contains coding sequences for <i>URA3</i> (gray) and <i>ARG4</i> (black). DSBs form in the promoter regions of <i>URA3</i> (DSB1) and <i>ARG4</i> (DSB2). The lollipop in <i>arg4</i> represents a palindromic sequence inserted at +9 of the open reading frame; this mutation is used to score gene conversion [<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.0020155#pgen-0020155-b016" target="_blank">16</a>].</p><p>(B) The ectopic recombination interval is inserted at <i>HIS4</i> (blue) on one copy of Chromosome III and at <i>LEU2</i> (red) on the homolog. <i>HIS4</i> and <i>LEU2</i> are 16.7 kilobases apart. In <i>rad50S</i> strains, where DSBs persist, 5% of chromosomes have a DSB in <i>his4::URA3-ARG4</i> and 0.7% have a DSB in <i>leu2::URA3-ARG4</i> [<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.0020155#pgen-0020155-b016" target="_blank">16</a>]. The centromere (black circle) and <i>MAT</i> locus (green) are also indicated. Allelic COs can be scored in the <i>HIS4-LEU2</i> and <i>LEU2-MAT</i> intervals.</p><p>(C) Ectopic COs can occur between <i>his4::URA3-ARG4</i> and <i>leu2::URA3-ARG4</i>.</p>