Fig. 1. pig-1 mutants have extra neurons derived from multiple lineages. (A) Schematic diagram of an L1 hermaphrodite: anterior to the left, dorsal up. Neurons produced from lineages affected in pig-1 mutants are indicated. (B) Lineages affected in pig-1 mutants. NB, neuroblast. PQR, PVM and SDQL are produced by the left Q neuroblast, and AQR, AVM and SDQR are produced by the right Q neuroblast. Note that the PVQ lineage is not affected in pig-1 mutants but is shown to indicate its relationship to the HSN/PHB lineage. (C) Lineages unaffected in pig-1 mutants. Neurons that were examined are shaded black. DD1,3,5 are produced on the left side of the body, and DD2,4,6 on the right. (B,C) Neurons were identified as described in the Materials and methods. Cells that were not scored are unshaded. (D-H) pig-1 mutants have extra neurons derived from the HSN/PHB neuroblast lineage. (D) Schematic diagram of the wild-type HSN/PHB neuroblast lineage. (E,F) Images of wild-type (E) and pig-1(gm301) (F) hermaphrodites stained with an anti-serotonin antiserum to visualize the HSNs (arrows). (G,H) Composite fluorescence and DIC images of wild-type (G) and pig-1(gm301) (H) hermaphrodites expressing the PHB-specific reporter gmIs22 [nlp-1::gfp] (arrows). Scale bar: 10 µm.