The fli-1 locus. (A) A genetic map of the fli-1 region. Numbers below the line indicate the number of recombination events between the loci in three-factor crosses. From dpy-17(e1264) unc-32(e189)/fli-1(ky535) trans-heterozygotes, 30/34 Dpy-non-Unc recombinants harbored ky535 and 10/99 Unc-non-Dpy recombinants harbored ky535. The estimated genetic distance between unc-32 and ky535 is 0.22 map units. (B) A diagram of the cosmid B0523. Genes on the cosmid are indicated as arrows. (C) The fli-1 gene. 5' is to the left. Black boxes indicate coding exons, and white boxes represent non-coding exons. The extent of the tm362 deletion is indicated below the line, as is the location of a Trp tRNA gene. The white box above the line indicates the region used in fli-1 RNAi experiments, and the black line represents 1 kb. The gene structure is derived from a fli-1 cDNA previously described (Genbank accession number U01183). (D) A diagram of the predicted FLI-1 polypeptide. The locations of the leucine-rich repeats (LRRs) and the five gelsolin-like repeats (G1–G5) are indicated. The deletion fli-1(tm362) removes coding region for the residues of FLI-1 indicated below the diagram. (E) A fli-1(tm362) homozygous embryo arrested before embryonic elongation. (F) A fli-1(tm362) homozygous mutant embryo arrested at the two-fold stage and showed a paralyzed arrest at two-fold (Pat) phenotype. The scale bar in (E) applies to (E) and (F).