SUN-1 cc regions counterbalance forces on the SUN-KASH bridge. (A) Midpachytene nuclei of sun-1(wt) and Psun-1(Δ158–235) II; sun-1(ok1282) V gonads 48 hr post-L4. DAPI (blue), SUN-1(green), and HIM-8 (red) costainings of gonads either treated with zyg-12  RNAi, untreated, or treated with empty vector control. White circles delineate the unpaired X chromosomes in case of RNAi treatment and the paired X chromosomes when treated with empty vector. Note the severe destruction of the gonad architecture in the absence of both SUN-1 and ZYG-12 in the mutant. (B) Costaining of DAPI (blue) and SUN-1 (red) in L4 gonads (undergoing spermatogenesis) of wild type and Psun-1(Δ158–235) II; sun-1(ok1282) V. Note the absence of the severe SUN-1 loss in the L4 gonads in the later stages of prophase I in the mutant. Bar, 10 µm.