After micro-injection of
Ce-chk-2 heterozygotes at the young adult stage with
Ce-rdh-1/rad-51 dsRNA, the F1 eggs laid 24 h after injection were collected and cultured until the young adult stage was reached. Chromosomes in mature oocytes isolated from each F1 adult (Rollers but not Unc) were stained with DAPI. 12 univalents were observed in all the oocyte of approximately 1/3 of F1 Rollers depleted for
Ce-rdh-1/rad-51, whereas structurally abnormal chromosomes were observed in all the oocytes of the remaining F1 Rollers. This result indicates that the
Ce-chk-2 phenotype (12 univalents without chiasmata) is epistatic to the
Ce-rdh-1/rad-51 phenotype (abnormalkinked chromosomes).