Fig. 1. dmd-3 acts with mab-3 to direct cell fusion and retraction of the male tail. (A) The dmd-3 locus and dmd-3 reporter genes. Thin gray lines indicate the dmd-3 promoter and 3' UTR; gray boxes mark exons. The two DM domains, the E(ht) enhancer element and the deletions in the dmd-3(tm2863) and dmd-3(ok1327) alleles are indicated. (B) DIC images of the tails of a wild-type adult male (i), wild-type adult hermaphrodite (ii), dmd-3(ok1327) adult male (iii,iv), mab-3(e1240) adult male (v) and mab-3(e1240); dmd-3(ok1327) adult male (vi). Representative examples of the two classes (short and long) of Lep tails observed in dmd-3 males are shown (iii,iv). (C) Individual wild type (i-iii), dmd-3 mutant (iv-vi) and mab-3; dmd-3 double mutant (vii-ix) L4 males were observed periodically by DIC microscopy. Tail-tip retraction is indicated by a bold white arrow; anterior tail retraction is indicated by a bold black arrow. Thin white and black arrows indicate the partial tail tip retraction and partial anterior tail retraction, respectively, seen in dmd-3 larvae. (D) Confocal images of wild-type (i,ii), dmd-3 mutant (iii,iv) and mab-3; dmd-3 mutant L4 males (v,vi) expressing the apical junction marker AJM-1::GFP. The broken line indicates the larval cuticle. Solid arrowheads indicate intact cell boundaries; broken arrowheads indicate cell fusions. (E) AJM-1::GFP/DIC images of the unretracted tail tips of an adult hermaphrodite (i), an adult dmd-3 male (ii) and an adult mab-3; dmd-3 male (iii). Arrowheads indicate intact cell boundaries.