RNA-Seq of eye tissue from a seasonally plastic temperate butterfly

Changes in sensory gene expression may underly seasonal changes in behavior. To accompany other research on seasonal changes in coloration and behavior in the seasonally plastic common buckeye butterfly Junonia coenia, we examined how gene expression in eyes differs between wild butterflies caught in summer and fall. We collected animals in 2019, 2020, and 2021 in the central United States. The samples consisted of three males and three females from each season: Summer (June/July) and Fall (late September/October) that had wing colors appropriate for previously described seasonal morphs (i.e. light in summer and dark in fall). We dissected eye tissue from butterfly heads and purified RNA prior to sending samples to Novogene for cDNA Library prep and RNA-Sequencing. We used DESeq2 for subsequent analysis. We found gene expression correlated to sex, season, and interactions between sex and season. Eye tissues from dark fall animals and light summer animals exhibit different patterns of expression in many genes including visual system development genes, pigmentation genes, and clock genes. This change in gene expression accompanies changes in basking behavior and wing color and indicates that J. coenia undergoes changes to its visual system depending on the seasonal environment.