Rosu, Simona A. Zawadzki, Karl L. Stamper, Ericca E. Libuda, Diana L. Reese, Angela F. Dernburg, Abby M. Villeneuve, Anne DSB-2 marked nuclei require RAD-50 for formation of RAD-51 foci after irradiation. <p>Immunofluorescence images of <i>rad-50</i> (A) and <i>htp-1; rad-50</i> (B) mutant gonads from the distal pre-meiotic region to end of pachytene, stained with DAPI and antibodies that recognize DSB-2 and RAD-51. Worms were fixed and stained 1 hour after exposure to 5 kRad of gamma-irradiation. A reciprocal relationship is observed between DSB-2 and RAD-51 immunolocalization: in nuclei where DSB-2 signal is detected on chromatin, formation of irradiation-induced RAD-51 foci is inhibited, and in nuclei where IR-induced RAD-51 foci are present, DSB-2 is absent. The zone of DSB-2 staining/RAD-51 inhibition is indicated by brackets. (Occasional bright RAD-51 foci in the “inhibited” zone are thought to represent pre-existing DNA damage acquired during mitotic cell cycles in mutants lacking RAD-50, as they are both irradiation- and SPO11-independent <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1003674#pgen.1003674-Hayashi1" target="_blank">[6]</a>.) Arrowheads point to examples of nuclei that retain DSB-2 staining/RAD-51 inhibition in a region of the germ line where their neighbors do not. Scale bar, 15 µm. While the zone of DSB-2 staining/RAD-51 inhibition in the irradiated <i>rad-50</i> single mutant extends from meiotic prophase entry to late pachytene, the zone of DSB-2 staining/RAD-51 inhibition is limited to a smaller domain from meiotic entry to the early pachytene region in the irradiated <i>htp-1; rad-50</i> double mutant.</p> marked;nuclei;rad-50;rad-51;foci 2013-08-08
    https://plos.figshare.com/articles/figure/_DSB_2_marked_nuclei_require_RAD_50_for_formation_of_RAD_51_foci_after_irradiation_/767732
10.1371/journal.pgen.1003674.g011