Stepwise co-option of gene networks drives morphological innovation in flies
This project investigates the evolutionary and developmental mechanisms underlying the emergence of the prothoracic respiratory organ (PROD) in dipteran insects, a structure proposed as a serial homolog of the insect wing. By integrating genomic, transcriptomic, and morphological data from over 200 species, including Deuterophlebia wuyiensis, Philorus sp., Aedes albopictus, and Drosophila melanogaster, we aim to unravel the stepwise co-option of gene regulatory networks (GRNs) that drive morphological innovation and complexity. Whole-genome sequencing of Deuterophlebia wuyiensis and Philorus sp. provides insights into genomic architecture, while RNA-Seq, SMART-seq2, and single-cell RNA-Seq data from PROD, wing, and whole-body tissues of Deuterophlebia wuyiensis, Aedes albopictus, and Drosophila melanogaster reveal shared and distinct GRNs governing these structures. Our findings link the emergence and modification of the PROD to major ecological events, such as the Carnian Pluvial Episode and the K-Pg mass extinction, highlighting the interplay between environmental pressures and evolutionary innovation. This study advances our understanding of how novel morphological traits arise through GRN co-option and provides a valuable resource for comparative genomics, evolutionary biology, and developmental studies across insect lineages.