title: Diploid and triploid African catfish (Clarias gariepinus) differ in biomarker responses to the pesticide chlorpyrifos.
abstract: The impacts of environmental stressors on polyploid organisms are largely unknown. This study investigated changes in morphometric, molecular, and biochemical parameters in full-sibling diploid and triploid African catfish (Clarias gariepinus) in response to chlorpyrifos (CPF) exposures. Juvenile fish were exposed to three concentrations of CPF (mean measured μg/L (SD): 9.71 (2.27), 15.7 (3.69), 31.21 (5.04)) under a static-renewal condition for 21days. Diploid control groups had higher hepatosomatic index (HSI), plasma testosterone (T), and brain GnRH and cyp19a2 expression levels than triploids. In CPF-exposed groups, changes in HSI, total weight and length were different between the diploid and triploid fish. In contrast, condition factor did not alter in any of the treatments, while visceral-somatic index (VSI) changed only in diploids. In diploid fish, exposure to CPF did not change brain 11β-hsd2, ftz-f1, foxl2, GnRH or cyp19a2 mRNA levels, while reduced tph2 transcript levels compared to the control group. In contrast, 11β-hsd2 and foxl2 expression levels were changed in triploids following CPF exposures. In diploids, plasma T levels showed a linear dose-response reduction across CPF treatments correlating with liver weight and plasma total cholesterol concentrations. In contrast, no changes in plasma cholesterol and T concentrations were observed in triploids. Plasma cortisol and 17-β estradiol (E2) showed no response to CPF exposure in either ploidy. Results of this first comparison of biomarker responses to pesticide exposure in diploid and polyploid animals showed substantial differences between diploid and triploid C. gariepinus.
authors.affiliation: Laboratory of Aquatic Toxicology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Selangor, Malaysia. Electronic address: alikaramiv@gmail.com.
authors.forename: Ali
authors.initials: A
authors.lastname: Karami
authors.affiliation: Department of Veterinary Preclinical Sciences, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 Selangor, Malaysia.
authors.forename: Yong-Meng
authors.initials: YM
authors.lastname: Goh
authors.affiliation: Laboratory of Animal Production, Institute of Tropical Agriculture, Universiti Putra Malaysia, 43400 Selangor, Malaysia.
authors.forename: Mohammad Faseleh
authors.initials: MF
authors.lastname: Jahromi
authors.affiliation: Office of Research and Development, National Exposure Research Laboratory, U.S. Environmental Protection Agency, Cincinnati, OH, United States.
authors.forename: James M
authors.initials: JM
authors.lastname: Lazorchak
authors.affiliation: Laboratory of Immunology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Selangor, Malaysia.
authors.forename: Maha
authors.initials: M
authors.lastname: Abdullah
authors.affiliation: School of Environment, Resources and Sustainability, Canadian Water Network, Canadian Rivers Institute, University of Waterloo, Canada.
authors.forename: Simon C
authors.initials: SC
authors.lastname: Courtenay
mesh_terms: D043209:11-beta-Hydroxysteroid Dehydrogenase Type 2 / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002397:Catfishes / Q000502:physiology*; D004390:Chlorpyrifos / Q000633:toxicity*; D004171:Diploidy; D004784:Environmental Monitoring; D004958:Estradiol / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D010575:Pesticides / Q000633:toxicity*; D013739:Testosterone / Q000378:metabolism; D057885:Triploidy
chemical_list: D015415:Biomarkers; D010575:Pesticides; D013739:Testosterone; D004958:Estradiol; D043209:11-beta-Hydroxysteroid Dehydrogenase Type 2; D004390:Chlorpyrifos
keywords: Biochemical; Gene expressions; Hormonal; Morphometric; Polyploidy