Molecular identification of a peroxidase gene controlling body size in the entomopathogenic nematodeSteinernema hermaphroditum

Abstract

AbstractThe entomopathogenic nematodeSteinernema hermaphroditumwas recently rediscovered and is being developed as a genetically tractable experimental system for the study of previously unexplored biology, including parasitism of its insect hosts and mutualism with its bacterial endosymbiontXenorhabdus griffiniae. Through whole-genome re-sequencing and genetic mapping we have for the first time molecularly identified the gene responsible for a mutationally defined phenotypic locus in an entomopathogenic nematode. In the process we observed an unexpected mutational spectrum following EMS mutagenesis in this species. We find that the ortholog of the essentialC. elegansperoxidase geneskpo-2controls body size and shape inS. hermaphroditum. We confirmed this identification by inactivating the gene using CRISPR-Cas9. We propose that the identification ofskpo-2will accelerate gene targeting in otherSteinernemaentomopathogenic nematodes used commercially in pest control, asskpo-2is X-linked and males hemizygous for loss of its function can mate, makingskpo-2an easily recognized and maintained marker for use in co-CRISPR.