(A) Projection images of mid-pachytene nuclei stained for RAD-51 (yellow) and DNA (blue), showing accumulation of DSB repair intermediates in the absence of ZHP-1 or ZHP-4. Scale bars, 5 µm. (B) Diagram of a hermaphrodite gonad, indicating the six zones in which RAD-51 foci were scored. (C–F) Quantification of RAD-51 foci. Gonads were divided into six zones of equal length, spanning the premeiotic through late pachytene region. The number of RAD-51 foci in each nucleus is presented for each zone. n = 167, 229, 160, 200, 133, 209, 100, 131, 87, 87, 44, 62, 222, 258, 227, 274, 190, 173, 158, 151, 109, 100, 68, 68, 352, 251, 283, 296, 197, 172, 167, 138, 124, 119, 76, 103, 338, 317, 281, 290, 227, 171, 194, 111, 134, 102, 74 and 102 nuclei, respectively, from zone 1 to zone 6, and zhp-1::AID to zhp-4::AID. four gonads were scored for each genotype or condition. **p=0.0084 and 0.0028, respectively, ***p<0.0001, Mann-Whitney test. (G–I) CHK-2 activity is extended in the absence of ZHP proteins. Low magnification images of gonads stained for pHIM-8/pZIMs (yellow) and DNA (blue). The upper gonad in each panel is a non-auxin treated control, while lower panels show gonads from animals depleted of ZHP-1 (G) or ZHP-4 (H) for ~24 hr. Scale bars, 5 µm. (I) Quantification of the ‘CHK-2 active zone,’ defined as the length of the region of pHIM-8/ZIM staining as a fraction of the region from meiotic onset to the end of pachytene before nuclei form a single file. n = number of gonads scored for each genotype or condition. *p=0.0199, **p=0.0018 and 0.0021, respectively, ***p<0.0001, two-sided Student t-test.