Toward Universal Forward Genetics: Using a Draft Genome Sequence of the Nematode To Identify Mutations Affecting Vulva Development.

Mapping-by-sequencing has become a standard method to map and identify phenotype-causing mutations in model species. Here, we show that a fragmented draft assembly is sufficient to perform mapping-by-sequencing in nonmodel species. We generated a draft assembly and annotation of the genome of the free-living nematode , a distant relative of the model We used this draft to identify the likely causative mutations at the -3 locus, which affect vulval development. The locus encodes the ortholog of , and we further show that mutants also have an unsuspected vulval-development phenotype. In a virtuous circle, we were able to use the linkage information collected during mutant mapping to improve the genome assembly. These results showcase the promise of genome-enabled forward genetics in nonmodel species.