Fig. 2: Mutations in pyr-1 cause a bulged tail phenotype in the grp-1(gm350) mutant.

A A schematic depicting the genetic screen designed to identify mutants with a bulged tail phenotype in the grp-1(gm350) sensitized background. One-day-old grp-1(gm350) adult worms were treated with ethylmethanesulfonate (EMS). The F1 progeny (heterozygotes) were isolated and their F2 progeny were screened for the bulged tail phenotype (homozygotes). B DIC images of pry-1(tp12) and pyr-1(tp12); grp-1(gm350) mutants. The percentages of mutants exhibiting the bulged tail phenotype are indicated on the top right corner. Scaled bar: 10 µm. C Mapping and cloning of pyr-1. The top panel shows a genetic map with five single nucleotide polymorphisms (SNPs) and the number of recombination events. The middle panel summarizes complementation tests using four deficiency strains. The bottom panel presents the results of rescue experiments using three fosmids (black rectangles) and a PCR-amplified pyr-1 fragment (open rectangle). D The rescue results of the PCR-amplified pyr-1 fragment are presented as the mean ± SD from three independent lines (n = 150 animals per line across three independent experiments). **** indicates P < 0.0001 (two-tailed t test). E Schematic representation of the PYR-1 protein domain structure. Amino acid positions and the mutations used in this study are indicated. Below, the catalytic steps of the de novo pyrimidine synthesis pathway mediated by different domains are shown. F Percentages of animals with a bulged tail phenotype for the indicated genotypes are shown. Data are presented as mean ± SD from at least three independent experiments (n = 50 animals per experiment). **** indicates P < 0.0001 (one-way ANOVA with Tukey’s multiple comparisons test). ns indicates no statistical difference (P > 0.05). The grp-1 allele used is gm350.