Animals are exposed to a variety of abiotic factors that can have devastating effects on an organismal life history traits. They have evolved complex multifarious protective mechanisms that allow them to cope and thrive in the face of such environmental insult. The Comparative Stress Physiology lab strives to understand how these mechanisms work under a variety of stressors, a combination of stressors, and repeated exposures of single or multiple stressors. Exposure length to certain stressors can have a protective effect on the organism, a concept termed physiological conditioning hormesis. Under hormesis there is a threshold to stress exposure that leads to negative fitness consequences but exposures below that threshold tend to be protective and lead to increases in fitness. In my lab, we take advantage of this protective nature of environmental stress and use a hormetic framework to address crucial questions (survival, health, and immunity). Rather than merely focusing on stress survival (24 or 48 hrs post exposure), my program also focuses on long-term effects of stress such as reproduction and longevity. Additionally, my lab explores the trans-generational effects of environmental stress and hormesis; where the F1 and F2 generations can benefit from hormesis experienced by the parental generation or suffer fitness consequences due to stress exposure of the parental generation. Elucidating the molecular mechanisms and epigenetic effects of stress defense and hormesis is essential for a thorough understanding of animal (including human) stress physiology.
Of particular interest to me is oxidative stress. The main way that environmental stress exerts its negative effect on organisms is through the formation of free radicals. Free radicals (and ROS) can continue to damage target tissues long after the environmental stressors ends. Thus, this delicate balance between prooxidants and antioxidants is essential for surviving periods of environmental stress and affects organismal performance, reproduction, and longevity.
Reactive oxygen species (ROS) are disproportionally generated during periods of environmental stress and can attack lipids, proteins, and DNA/RNA resulting in oxidative damage. This oxidative damage will have downstream performance effects on the organism affecting life history traits such as development, reproduction, and longevity. (from Benoit and Lopez-Martinez 2012)
Nectarivores uses nectar sugar to recharge their small molecular antioxidants in the absence of ample protein resources. Science 355: 733-735.
Low-oxygen hormesis shows great promise for phytosanitary irradiation.
Hormesis affects the dose required for successful sterile insect technique implementation.
Learn about how hormesis decreases irradiation-induced oxidative damage and increases lifespan and healthspan
Comparative Stress Physiology Lab publications
Department of Biology, New Mexico State University