Convergent and lineage-specific genomic changes shape adaptations in sugar-consuming birds

Convergent and lineage-specific genomic changes shape adaptations in sugar-consuming birds Abstract High-sugar diets cause human metabolic diseases, yet several bird lineages convergently adapted to feeding on sugar-rich nectar or fruits. We investigated the underlying molecular mechanisms in hummingbirds, parrots, honeyeaters, and sunbirds by generating nine new genomes and 90 tissue-specific transcriptomes. Comparative screens revealed an excess of repeated selection in both protein-coding and regulatory sequences in sugar-feeding birds, suggesting reuse of genetic elements. Sequence or expression changes in sugar-feeders affect genes involved in blood pressure regulation, lipid, amino acid and carbohydrate metabolism, with experiments showing functional changes in honeyeater hexokinase 3. MLXIPL, a key regulator of sugar and lipid homeostasis, showed convergent sequence and regulatory changes across all sugar-feeding clades; experiments revealed enhanced sugar-induced transcriptional activity of hummingbird MLXIPL, highlighting its adaptive role in high-sugar diets. Competing Interest Statement The authors have declared no competing interest. Footnotes ↵* co-first authors Main analyses revised. Main text and Figures revised. Supplemental files updated. Subject Area - Biochemistry (17725) - Bioengineering (13915) - Bioinformatics (42031) - Biophysics (21486) - Cancer Biology (18635) - Cell Biology (25548) - Clinical Trials (138) - Developmental Biology (13397) - Ecology (19937) - Epidemiology (2067) - Evolutionary Biology (24361) - Genetics (15619) - Genomics (22538) - Immunology (17763) - Microbiology (40468) - Molecular Biology (17206) - Neuroscience (88733) - Paleontology (667) - Pathology (2842) - Pharmacology and Toxicology (4834) - Physiology (7657) - Plant Biology (15172) - Synthetic Biology (4304) - Systems Biology (9831) - Zoology (2272)