A. Meiotic nuclei in early pachytene in wildtype and pch-2 mutant worms stained with DNA (blue) and antibodies against RAD-51 (red). B. Histograms representing the average number of RAD-51 foci per nucleus as a function of meiotic progression in wildtype and pch-2 mutant worms at 15°C (i), 20°C (ii) and 25°C (iii). Error bars indicate standard error of the mean. C. Histogram representing the percentage of nuclei with less than six GFP::COSA-1 foci per nucleus in wildtype and pch-2 mutant worms grown at 15°C, 20°C and 25°C. The number of nuclei assayed for each genotype are as follows: wildtype at 15°C, 303, at 20°C, 304, and 25°C, 339; pch-2 at 15°C, 318, at 20°C, 293, and 25°C, 360. D. A meiotic nucleus stained with DAPI (blue) with six GFP::COSA-1 foci (green). E. A meiotic nucleus stained with DAPI (blue) with five GFP::COSA-1 foci (green). F. Representative images of late meiotic nuclei without (top) and with (bottom) achiasmate chromosomes (arrows). G. Histogram representing the percentage of meiotic nuclei with achiasmate chromosomes in wildtype and pch-2 mutant worms grown at 15°C, 20°C and 25°C. The number of nuclei assayed for each genotype are as follows: wildtype at 15°C, 91, at 20°C, 156, and 25°C, 109; pch-2 at 15°C, 96, at 20°C, 170, and 25°C, 106. For all graphs, a * indicates a p value<0.05 and a ** indicates a p value of <0.0001. Significance was assessed by performing either a paired t-test (2B) or Fisher's exact test (2C).