title: Effects of atrazine exposure on male reproductive performance in Drosophila melanogaster.
abstract: Atrazine is a commonly utilized herbicide to control broadleaf weeds in the agricultural setting. It can, however, have negative effects on male reproductive performance in a variety of vertebrate species. Much less is known, however, about the effects of atrazine on invertebrates. In this study, we investigated the effects of several different concentrations of larval atrazine exposure on measures of reproductive performance in adult male Drosophila melanogaster. Atrazine exposure had significant effects on a male's mating ability and the number of eggs his partner laid when he was successful at mating. Exposed males also sired a smaller proportion of the offspring under competitive conditions when they were the first male to mate to a doubly mated female. Atrazine exposure had no measurable effect on a male's ability to prevent a mated female from mating to another male or on the proportion of offspring sired when the exposed males were the second male to mate. Exposure upregulated expression of one male reproductive gene, ovulin, but had no effect on expression of another, sex peptide. Exposed males produced and transferred more sex peptide protein to the female during mating but ovulin protein levels were not affected. In general, we observed non-monotonic responses such that the intermediate exposure levels showed the largest reduction in male reproductive performance. This study suggests that atrazine exposure affects male reproductive performance in insects and future studies should aim to understand the molecular mechanisms underlying the fitness effects of exposure.
authors.affiliation: Department of Biological Sciences, Binghamton University, Binghamton, NY 13902, USA. Electronic address: andrearvogel@gmail.com.
authors.forename: Andrea
authors.initials: A
authors.lastname: Vogel
authors.affiliation: Department of Biology, The College of Wooster, Wooster, OH 44691, USA. Electronic address: harper.jocque@ucdenver.edu.
authors.forename: Harper
authors.initials: H
authors.lastname: Jocque
authors.affiliation: Department of Biology, The College of Wooster, Wooster, OH 44691, USA. Electronic address: lsirot@wooster.edu.
authors.forename: Laura K
authors.initials: LK
authors.lastname: Sirot
authors.affiliation: Department of Biological Sciences, Binghamton University, Binghamton, NY 13902, USA. Electronic address: afiumera@binghamton.edu.
authors.forename: Anthony C
authors.initials: AC
authors.lastname: Fiumera
mesh_terms: D000818:Animals; D001280:Atrazine / Q000633:toxicity*; D029721:Drosophila Proteins / Q000378:metabolism; D004331:Drosophila melanogaster / Q000187:drug effects* / Q000502:physiology; D005260:Female; D015870:Gene Expression; D006540:Herbicides / Q000633:toxicity*; D007814:Larva / Q000187:drug effects / Q000502:physiology; D008297:Male; D012098:Reproduction / Q000187:drug effects; D012661:Semen / Q000737:chemistry; D012726:Sexual Behavior, Animal
chemical_list: D029721:Drosophila Proteins; D006540:Herbicides; D001280:Atrazine
keywords: Exposure; Non-monotonic; Seminal fluid protein; Sexual selection; Sperm competition; Toxicology