Dosage compensation in non-model insects - progress and perspectives

In many multicellular eukaryotes, heteromorphic sex chromosomes are responsible for determining the sexual characteristics and reproductive functions of individuals. Sex chromosomes can cause a dosage imbalance between sexes, which in some species is re-equilibrated by dosage compensation (DC). Recent genomic advances have extended our understanding of DC mechanisms in insects beyond model organisms such as Drosophila melanogaster. We review current knowledge of insect DC, focusing on its conservation and divergence across orders, the evolutionary dynamics of neo-sex chromosomes, and the diversity of molecular mechanisms. We propose a framework to uncover DC regulators in non-model insects that relies on integrating evolutionary, genomic, and functional approaches. This comprehensive approach will facilitate a deeper understanding of the evolution and essentiality of gene regulatory mechanisms.