| dc.description.abstract | Pigmentation is one of the traits that exhibits the most variation among animals and is commonly subjected to either or both, natural and sexual selection. Male-specific wing pigmentation, conferring mating advantage, displays an evolutionary association with frontal wing display across various Drosophila species groups. Though a genetic correlation between these traits has been suggested, the explicit genetic mechanism at the molecular level has remained elusive. The present study bridges this knowledge gap by investigating the genetic mechanisms underpinning the co- evolution of wing-spot and mating display in Drosophila, with a primary focus on D. elegans, the species with wing spots and wing display, and D. gunungcola, the sister species lacking both traits. As a crucial step, a reference-quality annotated genome was assembled for D. gunungcola, a species previously lacking such a resource. The PacBio Sequel platform enabled the sequencing of the inbred line of D. gunungcola, generating around 12 Gb of raw sequencing data and facilitating a nearly complete genome assembly at the chromosomal level. The genome assembly revealed a total of 13,950 protein-coding genes, indicating a high level of completeness when compared to other Drosophila species like D. melanogaster and D. elegans. This assertion is supported quantitatively through Benchmarking Universal Single-Copy Orthologs (BUSCOs) analysis, which showed 98.8% of BUSCOs present in full length. Further investigation into the olfactory receptor gene families in Drosophila disclosed intriguing genetic findings. Notably, the genes Or49a and OR67a, essential for olfaction, were found to be absent in flower-breeding sibling species within the Drosophila elegans species subgroup. The implications of these gene loss events could be far-reaching, potentially affecting ecological specialization and breeding habits, and hinting at a complex interplay between genetics, behavior, and ecological adaptation. Employing comparative transcriptomics, this study has unveiled genetic mechanisms potentially driving the co-evolution of wing spots and mating displays in D. elegans. The transcription factors bifid and fruitless, known to play roles in melanin biosynthesis and courtship behavior respectively, were found to be specifically upregulated in male D. elegans, a species known for its wing spots and mating displays. This thesis offers valuable insights into the genetics and evolution of Drosophila, with particular emphasis on trait co-evolution and ecological specialization. It not only underscores the value of advanced genomic technologies and methodologies, but also sets a platform for future investigations into the fascinating interplay between genetics, behavior, and ecological adaptations in Drosophila. | en_US |