Hormesis ultraviolet radiation and its effects on Drosophila melanogaster performance

Abstract

Hormesis can be protective as a multifarious response that results in upregulation of genes and organismal performance. The protective effects of hormesis in animal models includes improved survival, mating, extended longevity, and improved performance at old age (i.e. mating); amongst others. The sun is a source of energy used by terrestrial life in many trophic levels allowing for exposure to irradiation (UVR), a natural environmental stressor that increases production of reactive oxygen species (ROS) .This type of environmental stress is damaging by attacking lipids, proteins and DNA. Exposure to prolonged UVR conditions early in life (pupae) leads to changes in performance later in life. This response can be classified as preconditioning, pretreatment, conditioning, or cross tolerance. Previous studies scantily provide appropriate levels of exposure needed for UVR hormesis that would increase production of ROS and antioxidant enzymes. The age of the individual at the time of treatment can have dramatic effects on hormesis with low dose UVR effects that induce protection, an extension of normal life span and improved organismal performance shown in other insects. The vinegar fly, Drosophila melanogaster, was exposed to UVA at different intensities. Vials containing pupae, separated from food and kept in same vial were exposed to 0, 30, 45 or 60 minutes of ultraviolet radiation A (nm = 365). Different rates of UVA exposure (mW/m2), produced by the distance from the source, show slight differences in treatment survival/adult emergence and flight ability. Low doses of UVR lead to protective and beneficial responses, while exposures to high doses are damaging and detrimental. Ultimately, data such as these can be refined to develop a model of dose response that can be used to estimate hormesis, or the biphasic response.Support or Funding InformationNIH RISE 5R25GM061222‐19