(2nd Place) The effects of circadian clock genes on development and behavior of the European corn borer (Ostrinia nubilalis)

The timing of insects’ daily (feeding, movement) and seasonal (diapause, migration) rhythms affects their population dynamics and distribution. Yet, despite their implications for insect conservation and pest management, the genetic mechanisms underlying variation in timing are poorly understood. Prior research in a wide-spread corn pest, the European corn borer (Ostrinia nubilalis, ECB), identified strong associations between differences in timing of larval diapause, adult movement, and genetic variation at circadian clock genes: period and pigment-dispersing factor receptor (pdfr). Here, we leverage CRISPR/Cas9-mediated gene-editing of genetically diverse ECB to validate these genes and quantify the effect of specific alleles on daily and seasonal rhythms. Five period and pdfr knockout mutants were independently generated across two populations differing at period and pdfr. For each gene, reciprocal crosses between hemizygous mutant males and wild-type females carrying an alternate allele generated hybrid offspring for analysis. Whereby, comparing hemizygous hybrid male offspring from reciprocal crosses controls the genetic background and enabled precise evaluation of specific alleles at target genes. This presentation will share results from an ongoing study that tracked offspring (n = 608) over six months to examine the pleiotropic effects of these circadian clock gene alleles on larval and adult rhythms.