Decoding diversity: the role of structural variants, gene regulatory networks, and chromatin dynamics in shaping the evolution of <em>Heliconius</em> butterflies

Abstract

The genetic and regulatory mechanisms driving phenotypic diversity and speciation remain fundamental questions in evolutionary biology. This dissertation investigates the role of structural variants (SVs), gene regulatory networks (GRNs), and chromatin dynamics in shaping the evolution of <em>Heliconius</em> butterflies, a widely studied model for adaptive radiation and mimicry. Using a pan-genomic approach, I analyzed the genomic architecture of multiple <em>Heliconius</em> species, focusing on the impact of SVs on chromatin accessibility and gene regulation. The research reveals that SVs are significantly associated with lineage-specific chromatin modifications, suggesting a critical role in gene expression divergence. Additionally, comparative GRN analysis of wing color pattern genes highlights both conserved and divergent regulatory mechanisms underlying mimicry and adaptation. Through a combination of ATAC-seq, RNA-seq, and evolutionary genomics, I demonstrate that chromatin dynamics influence the speciation process. The findings underscore the complex interplay between structural genome evolution and regulatory adaptation, offering new insights into the molecular basis of phenotypic diversity. These results advance our understanding of how non-coding and structural genomic elements contribute to evolutionary processes, with broader implications for the study of genetic innovation and speciation.