Contrasting roles of transcription factors spineless and EcR in the highly dynamic chromatin landscape of butterfly wing metamorphosis

Background: We studied the chromatin accessibility landscsape in wings during butterfly metamorphosis, and investigate which transcription factors might be driving changes in accessibility Methods: We sequencing the Junonia coenia genome, and we studied chromatin accessibility using ATAC seq in multiple stages of wing development in both forewings and hindwings. For sites showing a large change in accessibility, we investigate which motifs are enriched, and correlate this with changes in gene expression of associated transcription factors. We confirm promising candidates with ChIP-seq Results: We find a highly dynamic landscape, with multiple peaks showing a double increase in accessibility throughout development. We show that transcription factor spineless, but not ecdysone receptor, is highly predictive of opening sites Conclusions: This work provides a characterization of the chromatin dynamics of insect wing metamorphosis, identifies novel candidate chromatin remodeling factors in insects, and provides the first genome assembly of the model butterfly Junonia coenia, with gene and cis-regulatory element annotations Overall design: RNA-seq from various tissues at various developmental stages.