Figure 1 .

LIN-39 and EFL-3 regulate programmed cell death in the ventral nerve cord. (A) The ventral nerve cord is derived from 12 P cell and 1 W cell lineages across the length of the animal. In the anterior (W, P1–P2) and posterior (P9–P12) lineages, some neurons undergo programmed cell death. (B) Each midbody (P3–P8) lineage is composed of five neuron types, which all survive in wild-type animals. Loss of lin-39 induces one neuron type, the VC, to express the cell death gene egl-1 and die in each midbody lineage, in addition to the seven that typically die in the posterior. In our screen, we identified that lin-39; efl-3(RNAi) animals have two additional neurons per midbody lineage expressing egl-1. (C) On unc-22 control RNAi, lin-39 animals express Pegl-1gfp in cells that undergo programmed cell death. In lin-39; efl-3(RNAi) animals, there is an increase in the number of neurons in the midbody and posterior expressing Pegl-1gfp. In efl-3(RNAi) animals, there is an increase in posterior neurons expressing Pegl-1gfp. Arrowheads indicate neurons expressing Pegl-1gfp in a lin-39 mutant background, and asterisks indicate additional neurons expressing Pegl-1gfp. All animals shown are also homozygous for ced-1; ced-3; Pegl-1gfp. Scale bars, 10 μm.