Description: Pleiotropy offers a unifying framework that reveals how seemingly unrelated traits can be linked through a single gene. One such group of genes in the class insecta are the pigmentation genes. My project will focus on understanding how tissue-specific regulation of pigmentation genes underlies variation in mating signals in Drosophila. Specifically, I will investigate three interrelated themes: (1) how pigmentation genes influence mating behavior, (2) the evolutionary consequences of pleiotropy across species and (3) the tissue-specific regulatory architecture that enables modular gene function. This project will identify which regulatory modules influence chemistry, colour, or both, providing empirical evidence for how modularity mitigates pleiotropic constraints. Additionally, comparative analysis in the D. americana group—where pigmentation and CHC divergence might contribute to incipient speciation —will place functional results in a macro-evolutionary context, asking whether the same pleiotropic variants are repeatedly recruited or whether selection favours lineage-specific solutions.