An animal toxin-antidote system kills cells by creating a novel cation channel
Fig 1
PMPL-1 is necessary for PEEL-1 toxicity in C. elegans.
(A) Selfish activity of the peel-1 zeel-1 toxin-antidote system in C. elegans shown in a genetic cross of strains from Bristol (which has the genetic element) and Hawaii (which lacks the genetic element). Hermaphrodite worms heterozygous for the presence of peel-1 zeel-1 (p(+) z(+)/p(−) z(−)) have 25% inviable progeny. This is due to sperm-delivered PEEL-1 toxicity causing developmental arrest of zeel-1(−) progeny. (B) Proportion of worms dying from ectopic, heat shock-PEEL-1 expression. Two pmpl-1 mutant alleles (yak103 and yak52) provide resistance to toxicity. (C) Proportion of dead, arrested embryos from self-fertilizing hermaphrodites heterozygous for peel-1 zeel-1. n = total progeny scored. (D) Predicted domain structure of the PMPL-1 protein with mutant alleles shown. The hydrophobic helices are predicted to be monotopic, passing through one leaflet of a lipid bilayer. (E) Body wall and vulval muscle (magenta) of pmpl-1(yak103) worms with vulval muscle-specific expression of PEEL-1 alone (top) or PEEL-1 and PMPL-1 (bottom). Vulval muscles appears normal with PEEL-1 alone but are missing or atrophied when PEEL-1 and PMPL-1 are co-expressed in these cells. All worms expressing PEEL-1 and PMPL-1 in vulval muscle cells had missing or severely deformed vulval muscles (n = 22). peel-1 and pmpl-1 are both GFP tagged. All channels are shown in S2D Fig. Scale bar = 20 µm. Underlying data are available in S1 Data.