Honey bees growing faster may mean dying younger

New study shows that transitions to aerobically-expensive behaviors in organisms living free in nature can have important consequences affecting the pace of aging. Reactive oxygen species (ROS) occur as a by-product of aerobic metabolism and impair cellular function by damaging proteins, nucleotides and lipids. Organisms possess a variety of anti-oxidant mechanisms to mitigate the effects of ROS, and the oxidative stress model of aging and senescence suggests that physiological performance declines with age due to lifetime accrual of ROS-induced damage and progressively limited anti-oxidant capacity. Hence, the onset, pace and duration of energetically-intense behaviors should affect lifetime kinetics of ROS-induced damage, anti-oxidant responses, physiological capacity and longevity.

A new study examines how these traits in honey bees are affected by age and behavioral intensity (factors which can be experimentally decoupled via manipulation of colony demographics), and is the first to use such an approach to test the oxidative stress model of aging in a free-living organism.

Background

Behavioral development in adult honeybees involves a stereotypical transition from energetically-inexpensive hive work to energetically-expensive foraging behavior at approximately 3 weeks of age. Each day after this transition, a foraging bee (which weighs only 80 mg, or roughly equivalent to a breath mint) will on average fly 8 km (5 miles), contract their wing muscles approximately 4,000,000 times, and reduce approximately 60 ml of pure oxygen in its thorax (the body segment housing the flight muscles). Age and foraging behavior should have strong affects on cellular oxidative stress and antioxidant mechanisms, especially in flight muscle, as well as functional senescence.

In this study the researchers used single-cohort colonies to experimentally manipulate the onset of foraging and compare markers of oxidative damage and antioxidant mechanisms among different tissues (head vs. thorax), age-matched behavioral groups (hive bees vs. foragers) and periods of the day (morning vs. afternoon), with the prediction that such markers are prevalent in high-intensity tissues, behaviors and day-time periods.

The study was conducted by Stephen P. Roberts, Michelle M. Elekonich and Jason B. Williams, all of the School of Life Sciences, University of Nevada Las Vegas. Their study was funded in part by the National Science Foundation (NSF) and the National Institutes of Health (NIH) and is entitled Oxidative stress and antioxidant mechanisms at the transition to an aerobically intensive lifestyle in honey bees. Dr. Roberts is presenting the team's preliminary findings at the 2008 American Physiological Society Intersociety Meeting The Integrative Biology of Exercise V. via American Physiological Society/EurekAlert.

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