title: Hawkmoths use nectar sugar to reduce oxidative damage from flight.
abstract: Nectar-feeding animals have among the highest recorded metabolic rates. High aerobic performance is linked to oxidative damage in muscles. Antioxidants in nectar are scarce to nonexistent. We propose that nectarivores use nectar sugar to mitigate the oxidative damage caused by the muscular demands of flight. We found that sugar-fed moths had lower oxidative damage to their flight muscle membranes than unfed moths. Using respirometry coupled with δ13C analyses, we showed that moths generate antioxidant potential by shunting nectar glucose to the pentose phosphate pathway (PPP), resulting in a reduction in oxidative damage to the flight muscles. We suggest that nectar feeding, the use of PPP, and intense exercise are causally linked and have allowed the evolution of powerful fliers that feed on nectar.
authors.affiliation: Department of Entomology, University of Arizona, Tucson, AZ, USA. levineran1@gmail.com.
authors.forename: E
authors.identifier: 0000-0002-9972-7028
authors.initials: E
authors.lastname: Levin
authors.affiliation: Department of Biology, New Mexico State University, Las Cruces, NM, USA.
authors.forename: G
authors.identifier: 0000-0002-7937-5002
authors.initials: G
authors.lastname: Lopez-Martinez
authors.affiliation: School of Plant Sciences and the BIO5 Institute, University of Arizona, Tucson, AZ, USA.
authors.forename: B
authors.initials: B
authors.lastname: Fane
authors.affiliation: Department of Entomology, University of Arizona, Tucson, AZ, USA.
authors.forename: G
authors.initials: G
authors.lastname: Davidowitz
mesh_terms: D000332:Aerobiosis; D000818:Animals; D019422:Dietary Sucrose / Q000378:metabolism*; D005247:Feeding Behavior; D005426:Flight, Animal; D005947:Glucose / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D019803:Glutathione Disulfide / Q000378:metabolism; D009036:Moths / Q000378:metabolism / Q000502:physiology*; D009132:Muscles / Q000378:metabolism; D018384:Oxidative Stress; D010427:Pentose Phosphate Pathway; D057048:Plant Nectar / Q000378:metabolism*
chemical_list: D019422:Dietary Sucrose; D057048:Plant Nectar; D005978:Glutathione; D005947:Glucose; D019803:Glutathione Disulfide