Relationship between reproductive success and male plasma vitellogenin concentrations in cunner, Tautogolabrus adspersus.

Abstract

The gene for vitellogenin, an egg yolk protein precursor, is usually silent in male fish but can be induced by estrogen exposure. For this reason, vitellogenin production in male fish has become a widely used indicator of exposure to exogenous estrogens or estrogen mimics in the aquatic environment. The utility of this indicator to predict impacts on fish reproductive success is unclear because information on the relationship between male plasma vitellogenin and reproductive end points in male and female fish is limited. In the research reported in this article, we investigated whether the presence of male plasma vitellogenin is a reliable indicator of decreased reproductive success in mature fish. Adult and sexually mature male and female cunner (Tautogolabrus adspersus) were exposed to 17ss-estradiol, ethynylestradiol, or estrone, three steroidal estrogens that elicit the vitellogenic response. Data were gathered and pooled on egg production, egg viability, egg fertility, sperm motility, and male plasma vitellogenin concentrations. All males, including two with plasma vitellogenin levels exceeding 300 mg/mL, produced motile sperm. Neither percent fertile eggs nor percent viable eggs produced by reproductively active fish demonstrated a significant correlation with male plasma vitellogenin concentrations. Male gonadosomatic index and average daily egg production by females showed significant, but weak, negative correlation with male plasma vitellogenin concentrations. Results suggest that male plasma vitellogenin expression is not a reliable indicator of male reproductive dysfunction in adult cunner exposed to estrogens for 2-8 weeks during their reproductive season, at least in relation to capacity to produce motile sperm or fertilize eggs. Male plasma vitellogenin expression may serve as an indicator of reduced female reproductive function caused by estrogen exposure.

Comparative responses to endocrine disrupting compounds in early life stages of Atlantic salmon, Salmo salar

“…Elevated Vtg outside of the normal period of reproduction is strongly associated with negative impacts to fitness such as depressed growth (Leet et al, 2011), altered gonad morphology and function (Tyler and Routledge, 1998;Tyler and Jobling, 2008), and reproductive success (Mills et al, 2003). In some cases, the accumulation of Vtg in circulation can impair liver function and lead to pathological changes in the liver, kidney and testes (Folmar et al, 2001;Palace et al, 2002).…”

Evidence for estrogenic endocrine disruption in an offshore flatfish, the dab (Limanda limanda L.)

“…Some male flounders with elevated VTG concentrations have also been 12 caught in the open sea (Allen et al, 1999a), but these were hypothesised to be fish that had recently emigrated from a contaminated estuary. In estuarine and coastal areas of the USA (Mills, Gutjahr-Gobell, Horowitz, Denslow, Chow, & Zaroogian, 2003;Roy, Armstrong, Sakamoto, Steinert, Perkins, Lomax et al, 2003) and Japan (Hashimoto, Bessho, Hara, Nakamura, Iguchi, & Fujita, 2000;Hara, Matsubara, & Soyano, 2001;Ohkubo, Mochida, Adachi, Hara, Hotta, Nakamura et al, 2003), many male fish have also been found with high concentrations of VTG in their plasma.…”

Stimulation of reproductive growth in rainbow trout (Oncorhynchus mykiss) following exposure to treated sewage effluent

“…Studies have led to the concIusion that severe impacts of endocrine disrtlptors on the population level remain questionable ( [15]; http://europa.eu.int/comm/research/ endocrine/projects-completecLen.html) or have concluded that the impact of sewage eftluent on reproductioll in adult fishes is quite minor [16,17]. A study l1sing pure estrogens showed that induction even of high levels of vitellogenin in male cunHer (Tautogolabrus adsperslls) does not cause signHicant reproductive alterations [18], aIthough high levels of plasma vitellogenin have been associated with Iiver damage in flounder (Paralichthys dentatus) [19].…”