title: Developmental timing of sodium perchlorate exposure alters angiogenesis, thyroid follicle proliferation and sexual maturation in stickleback.
abstract: Perchlorate, a common aquatic contaminant, is well known to disrupt homeostasis of the hypothalamus-pituitary-thyroid axis. This study utilizes the threespine stickleback (Gasterosteus aculeatus) fish to determine if perchlorate exposure during certain windows of development has morphological effects on thyroid and gonads. Fish were moved from untreated water to perchlorate-contaminated water (30 and 100mg/L) starting at 0, 3, 7, 14, 21, 42, 154 and 305 days post fertilization until approximately one year old. A reciprocal treatment (fish in contaminated water switched to untreated water) was conducted on the same schedule. Perchlorate exposure increased angiogenesis and follicle proliferation in thyroid tissue, delayed gonadal maturity, and skewed sex ratios toward males; effects depended on concentration and timing of exposure. This study demonstrates that perchlorate exposure beginning during the first 42 days of development has profound effects on stickleback reproductive and thyroid tissues, and by implication can impact population dynamics. Long-term exposure studies that assess contaminant effects at various stages of development provide novel information to characterize risk to aquatic organisms, to facilitate management of resources, and to determine sensitive developmental windows for further study of underlying mechanisms.
authors: Department of Biological Sciences, University of Alaska Anchorage, 3211 Providence Dr., Anchorage, AK 99508, USA; Department of Biology and Wildlife, University of Alaska Fairbanks, 902 N. Koyukuk Dr., P.O. Box 757000, Fairbanks, AK 99775, USA. Electronic address: bfurin@gmail.com.
authors: Christoff G
authors: CG
authors: Furin
authors: Department of Biological Sciences, University of Alaska Anchorage, 3211 Providence Dr., Anchorage, AK 99508, USA. Electronic address: favonhippel@uaa.alaska.edu.
authors: Frank A
authors: FA
authors: von Hippel
authors: Institute of Neuroscience, University of Oregon, 1254 University of Oregon, 324 Huestis Hall, Eugene, OR 97403, USA. Electronic address: jpostle@uoneuro.uoregon.edu.
authors: John H
authors: JH
authors: Postlethwait
authors: Department of Biological Sciences, University of Alaska Anchorage, 3211 Providence Dr., Anchorage, AK 99508, USA.
authors: C Loren
authors: CL
authors: Buck
authors: Institute of Ecology and Evolution, University of Oregon, 312 Pacific Hall, Eugene, OR 97403, USA. Electronic address: wcresko@uoregon.edu.
authors: William A
authors: WA
authors: Cresko
authors: Department of Veterinary Medicine, University of Alaska Fairbanks, P.O. Box 757750, Fairbanks, AK 99775-7750, USA. Electronic address: tmohara@alaska.edu.
authors: Todd M
authors: TM
authors: O'Hara
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D005260:Female; D006066:Gonads / Q000254:growth & development*; D008297:Male; D010472:Perchlorates / Q000378:metabolism*; D012098:Reproduction; D012741:Sexual Maturation; D023701:Smegmamorpha / Q000235:genetics* / Q000378:metabolism*; D017670:Sodium Compounds / Q000378:metabolism*; D013961:Thyroid Gland / Q000378:metabolism*; D014874:Water Pollutants, Chemical
chemical_list: D010472:Perchlorates; D017670:Sodium Compounds; D014874:Water Pollutants, Chemical; C031068:sodium perchlorate
keywords: Endocrine disruption; Gasterosteus aculeatus; Histology; Ovary; Testis; Thyroid hormone