Preprint finds copper resistance in Drosophila comprises independently varying behavioural and physiological components

A preprint on bioRxiv from researchers using the Drosophila Synthetic Population Resource (DSPR) examines the genetic architecture of copper resistance in Drosophila melanogaster. Anthropogenic copper contamination from agricultural, mining, and industrial sources creates environmental gradients that wild fly populations must navigate, making this an accessible system for studying the genetics of ecotoxicological adaptation.

The study measured three components of the copper response in a panel of recombinant inbred lines (RILs): feeding avoidance (the extent to which flies reduce food intake on copper-laced medium), oviposition avoidance (the extent to which females avoid laying eggs on copper-contaminated substrate), and physiological tolerance (quantified as median lethal time, LT50, on high-copper medium). RILs are laboratory-generated strains with known, fixed genomes that enable mapping of genetic variants to quantitative trait differences.

The authors report that the three resistance components show largely independent genetic variation across the RIL panel, implying that copper resistance is not a single integrated trait but a collection of behaviourally and physiologically distinct responses that can evolve along separate trajectories. This finding is relevant to evolutionary genetics, ecotoxicology, and the broader question of how multidimensional environmental challenges shape genome-level adaptation.

The preprint has not yet been peer-reviewed.