Fig. 3.

Effect of small molecules on chromosome recombination frequencies in allotetraploid cells. The small molecules camptothecin, ML216, and mitomycin C were assessed for their effect on intraspecific and interspecific recombination. (A) Allotetraploid cells (Center) were treated with BrdU and small molecules to measure intraspecific SCE events by microscopy (Left), or treated with Cas9 and gRNAs with or without ML216 followed by haplotagging to identify interspecific recombinant molecules by sequencing (Right) (Materials and Methods). (B) The proportion of chromosomes that had SCE events after treatment with the indicated concentrations of each small molecule is listed (recomb. prop.). N denotes number of replicate experiments where the recomb. prop. was quantified for all concentrations or the best concentration (when indicated). Note that BrdU was added to all cells to visualize SCE, and all BrdU+drug treatments were compared to the BrdU-only condition (ratio to ctrl). For haplotagging, the effect of CRISPR guides targeting specific loci was assessed with or without ML216. Compared to CRISPR alone, ML216 may elevate the proportion of interspecific recombinant molecules genome wide (ratio to ctrl). Values are mean ± SEM.