title: Genomic investigation of year-long and multigenerational exposures of fathead minnow to the munitions compound RDX.
abstract: We assessed the impacts of exposure to an environmentally representative concentration (0.83 mg/L) of the explosive cyclotrimethylenetrinitramine (RDX) on fathead minnows (Pimephales promelas) in one-year and multigenerational bioassays. In the one-year bioassay, impacts were assessed by statistical comparisons of females from breeding groups reared in control or RDX-exposure conditions. The RDX had no significant effect on gonadosomatic index or condition factor assayed at 1 d and at one, three, six, nine, and 12 months. The liver-somatic index was significantly increased versus controls only at the 12-month timepoint. RDX had no significant effect on live-prey capture rates, egg production, or fertilization. RDX caused minimal differential-transcript expression with no consistent discernable effect on gene-functional categories for either brain or liver tissues in the one-year exposure. In the multigenerational assay, the effects of acute (96 h) exposure to RDX were compared in fish reared to the F(2) generation in either control or RDX-exposure conditions. Enrichment of gene functions including neuroexcitatory glutamate metabolism, sensory signaling, and neurological development were observed comparing control-reared and RDX-reared fish. Our results indicated that exposure to RDX at a concentration representing the highest levels observed in the environment (0.83 mg/L) had limited impacts on genomic, individual, and population-level endpoints in fathead minnows in a one-year exposure. However, multigenerational exposures altered transcript expression related to neural development and function. Environ.
authors.affiliation: Environmental Laboratory, US Army Engineer Research and Development Center, Vicksburg, Mississippi, USA. kurt.a.gust@erdc.usace.army.mil
authors.forename: Kurt A
authors.initials: KA
authors.lastname: Gust
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Brasfield
authors.forename: Jacob K
authors.initials: JK
authors.lastname: Stanley
authors.forename: Mitchell S
authors.initials: MS
authors.lastname: Wilbanks
authors.forename: Pornsawan
authors.initials: P
authors.lastname: Chappell
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Perkins
authors.forename: Guilherme R
authors.initials: GR
authors.lastname: Lotufo
authors.forename: Richard F
authors.initials: RF
authors.lastname: Lance
mesh_terms: D000818:Animals; D001681:Biological Assay; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D003530:Cyprinidae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure / Q000032:analysis; D053834:Explosive Agents / Q000378:metabolism / Q000633:toxicity*; D005260:Female; D005306:Fertilization; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D016678:Genome / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D014227:Triazines / Q000378:metabolism / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*
chemical_list: D053834:Explosive Agents; D029941:Fish Proteins; D014227:Triazines; D014874:Water Pollutants, Chemical; C009160:cyclonite