Abstract
Insect metamorphosis is a complex developmental process regulated by hormonal signaling and gene transcription. To elucidate its transcriptional regulatory mechanisms, we examined chromatin accessibility dynamics during metamorphosis in two holometabolous insects, Harmonia axyridis and Drosophila melanogaster, using ATAC-seq. Our analysis revealed distinct stage-specific chromatin accessibility patterns, with peak accessibility during the prepupal stage in H. axyridis and the wandering larval to prepupal transition in D. melanogaster. Through analysis of differential accessibility regions (DARs), we identified enrichment of metamorphosis-related processes including cell morphogenesis, tissue remodeling, and hormone signaling pathways via Gene Ontology and KEGG pathway analyses. Integration of chromatin accessibility with gene expression data revealed 608 conserved genes exhibiting coordinated accessibility and expression changes across both species. Additionally, we constructed a regulatory network centered around four key transcription factors (dsx, E93, REPTOR, and Sox14) that form core regulatory modules controlling metamorphosis. This study provides novel insights into the epigenetic landscape of insect metamorphosis and establishes a foundation for understanding the transcriptional regulatory mechanisms governing this critical developmental process.
