|Li-byarlay1, Hongmei - North Carolina State University|
|Huang, Ming Hua - North Carolina State University|
|Strand, Micheline - Us Army Research Institute Of Environmental Medicine|
|Tarpy, David - North Carolina State University|
|Rueppell, Olav - University Of North Carolina|
Submitted to: Experimental Gerontology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/11/2016
Publication Date: 7/11/2016
Citation: Li-Byarlay1, H., Huang, M., Simone-Finstrom, M., Strand, M.K., Tarpy, D.R., Rueppell, O. 2016. Honey bee (Apis mellifera) drones survive oxidative stress due to increased tolerance instead of avoidance or repair of oxidative damage. Experimental Gerontology 83:15-21.
Interpretive Summary: Aging in organisms, like honey bees is associated with the accumulation of damage resulting from oxidative stress. Oxidative stress is the result of the production of free radicals during metabolism, and these free radicals damage proteins and even DNA. Some individuals, however, are better able to tolerate oxidative damage, while others still are better able to resist damage through antioxidant based defenses. Currently it is unclear whether stress-resistant or long-lived individuals avoid, repair, or tolerate molecular damage to survive longer than others. Likewise, the relationship between environmental and genetic factors that affect the oxidative stress resistance of organisms remains to be elucidated. The honey bee (Apis mellifera L.) is an underused model system to address these questions, as well as being economically important as pollinators. Moreover, oxidative stress in honey bees exposed to pesticides and herbicides may be a contributing factor in the widespread mortality in honey bee populations. Here, we developed a protocol for inducing oxidative stress in honey bee males (drones) via Paraquat injection, an herbicide that is known to induce oxidative damage. Our results are the first to address oxidative stress in males of honeybees and demonstrates that colonies differ in oxidative stress resistance. Furthermore, the results suggest that survival of oxidative stress in male honey bees is due to tolerance, not prevention or repair, of oxidative damage.
Technical Abstract: Oxidative stress can lead to premature aging symptoms and cause acute mortality at higher doses in a range of organisms. Oxidative stress resistance and longevity are mechanistically and phenotypically linked: considerable variation in oxidative stress resistance exists among and within species and typically covaries with life expectancy. However, it is unclear whether stress-resistant, long-lived individuals avoid, repair, or tolerate molecular damage to survive longer than others. The honey bee (Apis mellifera L.) is an emerging model system that is well-suited to address this question. Furthermore, this species is the most economically important pollinator, whose health may be compromised by pesticide exposure, including oxidative stressors. Here, we develop a protocol for inducing oxidative stress in honey bee males (drones) via Paraquat injection. After injection, individuals from different colony sources were kept in common social conditions to monitor their survival compared to saline-injected controls. Oxidative stress was measured in susceptible and resistant individuals. Paraquat drastically reduced survival but individuals varied in their resistance to treatment within and among colony sources. Longer-lived individuals exhibited higher levels of lipid peroxidation than individuals dying early. In contrast, the level of protein carbonylation was not significantly different between the two groups. This first study of oxidative stress in male honey bees suggests that survival of an acute oxidative stressor is due to tolerance, not prevention or repair, of oxidative damage to lipids. It also demonstrates colony differences in oxidative stress resistance that might be useful for breeding stress-resistant honey bees.