DSB-2 and SUN-1 S8P persist in mutants defective for DSB repair.

<p>Immunofluorescence images of gonads of indicated genotypes from the distal pre-meiotic region to end of pachytene, stained with DAPI and antibodies that recognize DSB-2 and SUN-1 S8P. The zone of DSB-2 and SUN-1 S8P-positive nuclei is extended in all three mutants depicted: (A) <i>rad-50</i>, which is defective in both DSB formation and DSB repair; (B) and (C) <i>rad-51</i> and <i>rad-54</i>, which are defective in DSB repair. In the <i>rad-50</i> mutant germ line, pachytene nuclei have variable staining intensities, with some bright DSB-2 and/or SUN-1 S8P-positive nuclei scattered over the entire pachytene zone; this likely reflects the fact that although the <i>rad-50</i> mutant lacks SPO-11-dependent DSBs, many nuclei enter meiotic prophase with existing DNA damage resulting from failure to repair lesions arising during DNA replication <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1003674#pgen.1003674-Hayashi1" target="_blank">[6]</a>. DSB-2 staining persists until the end of the pachytene region of the <i>rad-51</i> and <i>rad-54</i> mutant gonads, which are also shorter than the gonads of wild-type controls. Scale bar, 15 µm.