Prolonged CHK-2 activity and abnormal crossover designation in syp-5 ^S541A syp-6 ^T685A mutants. (A and B) Graphs showing the percent viable and male self-progeny from wild type (n = 1,921), syp-5^S541A (n = 2,617), syp-6^T685A (n = 3,022), and syp-5^S541Asyp-6^T685A mutants (n = 1,526) hermaphrodites. **, P < 0.01; ***, P < 0.001; ****, P < 0.0001 by unpaired t test. (C) Immunofluorescence images from wild type and syp-5^S541Asyp-6^T685A mutants stained for DNA (blue) and HIM-8 (red). Scale bar, 5 µm. (D) Dissected gonads from wild type and syp-5^S541Asyp-6^T685A mutants were stained for DNA and phospho-HIM-8/ZIMs (CHK-2 substrate). Composite projection immunofluorescence images are shown. The CHK-2 active zone is marked by yellow dotted lines. Scale bar, 50 µm. (E) Graph showing the CHK-2 active zone in wild type and syp-5^S541Asyp-6^T685A mutants, shown as a percent gonad length of the pHIM-8/ZIM-positive region relative to the region from meiotic entry to pachytene exit. The numbers of gonads scored are also indicated. **, P < 0.05 by unpaired t test. (F) Immunofluorescence images of pachytene nuclei from wild type and syp-5^S541Asyp-6^T685A animals stained for DNA (blue) and GFP::COSA-1 (green). Scale bar, 5 µm. (G) Graph showing the quantification of GFP::COSA-1 foci per nucleus. The numbers of nuclei scored are indicated on the top.