zhp-4 mutants show elevated levels of the homologous recombination protein RAD-51 throughout prophase.

(A) The number of RAD-51 foci were scored in each nucleus of a gonad from individuals of the indicated genotype, from the distal tip cells until the end of pachytene. Each gonad was then divided into six equivalent zones that are largely populated by nuclei in the following stages: mitotic region (zones 1 and 2), transition zone-early pachytene region (zone 3) and mid through-late pachytene regions (zones 4–6). As in wild-type, RAD-51 foci in zhp-4 mutants first appear in zone 3, but at higher levels that remain statistically higher until zone 5 (p<0.001). At very late pachytene (zone 6), these elevated RAD-51 foci in the null allele vv103 are reduced to wild-type levels (ns, p>0.05), whereas vv96 mutants retain elevated numbers of RAD-51-marked recombination intermediates (p<0.001). Three gonads were analyzed for each genotype (Mann-Whitney test, *** p<0.001). (B) Immunolocalization of RAD-51 (green) and axis component HTP-3 (red) in representative nuclei from mid-pachytene (zone 4) and late pachytene (zone 6) stages from germlines corresponding to the genotypes in (A). Scale bars 5 μm.