Effects of environmental lead on the blood proteome of sparrows in Broken Hill

Lead (Pb) is a global environmental pollutant, responsible for millions of deaths each year. Elevated lead levels in Australian mining towns, such as Broken Hill and Mount Isa, are severe hazards to human and wildlife health. Living organisms, including animals, have the ability to evolve to resist the negative effects imposed by the environmental stressors like lead. Sparrows are well known for their invasions and adaptations to new environments, including polluted environments. One such example includes the establishment of sparrow populations in lead polluted towns of Broken Hill and Mount Isa in Australia. We hypothesized that lead toxicity induces stress adaptive response in sparrows by regulating the avian proteome to withstand the high lead levels in these towns. To test this hypothesis, we optimized protocols for shotgun proteomics analysis of avian serum and frozen blood. Optimized protocols were then used for shotgun proteomics analysis of serum, frozen whole blood, and blood pellets of sparrows from Broken Hill. By comparing the blood proteome of sparrows with high and low blood lead levels, we identified 13 differentially expressed proteins. At least six proteins, including ferritin, DNA lyase and ribosomal proteins, can be linked to traits related to lead and other heavy metal adaptation.