Fig. 2. (A) ref-2(mu218) was mapped to the black regions in the top two panels, as described in Materials and Methods. Ultimately, an 8 kb PCR product was identified that induced the mutant phenotype in the progeny of injected worms (bottom panel). Only a single open reading frame is predicted on this DNA. The verified cDNA structure is indicated with exons depicted as boxes. Gray boxes indicate the region where the five zinc fingers are encoded. The 3' UTR is indicated by hatching. The GA transition present in mu218 DNA is also depicted. Scale is indicated in the right-hand corner of each panel. (B) Anti-rescue was achieved by injecting DNA containing the mu218 GA transition (middle) but not by injecting wild-type DNA (top), or DNA containing both the GA transition and the TGAT insertion (which introduces stop codon and a frameshift prior to the first zinc finger). Anti-rescue indicates that P7.p and P8.p remained unfused in males.