) Positional mapping of gg661, gg662 and gg633. Mutant animals were crossed with a mapping strain (see Materials and Methods). Progeny were subjected to dpy-11 RNAi and non-Dpy F2 progeny were pooled and genomic DNA isolated from pooled animals was subjected to whole genome sequencing. Y axis shows the percentage of sequence reads that harbored mapping strain single nucleotide polymorphisms (SNPs) as a function of the total number of reads that contained each SNP. The red line is a LOESS regression line through all the SNP points on Chr I. The data show that all three alleles are linked to the left arm of chromosome I. 