Long-Range Regulatory Polymorphisms Affecting a GABA Receptor Constitute a Quantitative Trait Locus (QTL) for Social Behavior in Caenorhabditis elegans
(A) Behavior of N2 animals (left), HW animals (middle), and HW animals with the N2 npr-1 allele (right). Photographs were taken three days after three adult hermaphrodites produced self-progeny on plates seeded with E. coli OP50. Scale bar, 2 mm. Insets show individual solitary N2 animals, a group of aggregating HW animals, and aggregating and non-aggregating animals from the HW strain with the N2 npr-1 allele. For genotypes in all figures, red denotes N2 DNA, blue denotes HW DNA. (B) Bordering and aggregation behaviors of npr-1 near-isogenic lines (NILs) and of chromosome-substitution strains. In this and other figures, bordering and aggregation were measured on 150 adult animals two hours after transferring to E. coli OP50 seeded plates (see Methods); values represent the mean of at least three assays per strain. Error bars, s.e.m. * P<0.05, ** P<0.01, *** P<0.001, by ANOVA with Bonferroni test. ns, not significant. (C) Behaviors of 102 N2-HW recombinant inbred advanced intercross lines (RIAILs) that carry the N2 npr-1 allele. (D) QTL analysis of RIAILs shown in (C). The horizontal line denotes the P<0.05 genome-wide significance threshold. lod, log likelihood ratio.