Genomics of convergent evolution of nectar-feeding

How did birds adapt their metabolism to excessive sugar consumption evading adverse consequences, which in humans would inevitably lead to type 2 diabetes? Did independent bird lineages evolve similar molecular solutions to challenges associated with nectar feeding? To answer these questions, we combined genome sequencing, comparative genomics and transcriptomics across four nectivorous clades. We also designed and performed functional tests to validate the potential role of selected gene candidates in the evolution of nectarivory in birds.

We found:

  • higher molecular convergence in nectar birds
  • positive selection on MLXIPL - a major regulator of sugar and lipid metabolism
  • high effect of regulatory evolution on lipid and protein metabolism
  • high effect of both sequence and regulatory evolution on heart function and sugar metabolism
Continue reading on bioRxiv…

Evolution of hummingbirds' extreme metabolic and flight adaptations

Hummingbirds have the fastest metabolic rates among vertebrates. Some of them can consume up to three times their body mass of flower nectar per day. They use these immense amounts of just-consumed nectar to fuel their energy-expensive hovering flight. However, while why hummingbirds drink so much flower nectar is no mystery, how they convert it to energy literally on the fly and avoid any health consequences from their high sugar consumption is. I tried to solve these mysteries by studying the genomes of hummingbirds and comparing them with the genomes of other birds.

We found:

  • all hummingbirds lost FBP2 - a key glyconeogenic enzyme
  • downregulation of FBP2 in a model system enhances glycolysis and mitochondrial respiration
Continue reading Osipova et al, 2023…

Genomic causes and consequences of brood parasitism in birds

What can birds that don’t raise their own chicks teach us about evolution? We explored the genomics behind the radical reproductive strategy: brood parasitism. Using population genomic data from five parasitic birds, spanning three independent origins of the trait, we found strikingly similar patterns of selection across lineages.

We found:

  • 💦 Repeated adaptation in genes involved in spermatogenesis
  • 🧠 Repeated selection near genes involved in brain and neural development
These patterns suggest strong evolutionary pressures on both reproduction and cognition in brood parasites. More broadly, our results show that even complex behavioral traits can leave repeated genetic signatures.