Experimental Evaluation of Vitellogenin as a Predictive Biomarker for Reproductive Disruption

• DOI: 10.2307/3454784
• Publication Date: 2007-03-10T03:58:13Z
• Authors: Ann Oliver Cheek; Thea Hoexum Brouwer; Suzanne Carroll; Steve Manning; John A. McLachlan; Marius Brouwer
• Keywords: Vitellogenin; Oviparity; Feminization (sociology); Xenoestrogen; Sexual maturity; Endocrine disruptor; Oryzias

Vitellogenin (VTG) synthesis in male oviparous vertebrates is used as an indicator of environmental estrogen exposure, but the relationship between elevated VTG levels and effects estrogens on reproductive success are poorly understood. To examine whether altered expression predicts impairment, we exposed medaka (Oryzias latipes) for 2 or 8 weeks posthatch to 0, 0.5, 1.0, 2.5, 7.5 ppb o,p'-DDT. Fish were sampled 2, 4, after hatch gonad development. After fish transferred clean water, grown sexual maturity, placed mating pairs. We collected eggs 7 days scored them fecundity (number eggs), fertility (percent fertilized), hatching hatched). DDT had no effect a 2-week whereas all doses induced weeks. At both exposure durations, highest caused female-skewed sex ratio adults. Gonadal feminization appeared be progressive: some ovotestes observed 2- 4-week two doses, proportion ovaries increased Both 8-week exposures significantly reduced at with lower having greater longer exposure. Fertility more sensitive estrogenic disruption than differentiation vitellogenin expression. suggest that may interpreted warning consequences, absence cannot consequences.