Differential effects of bisphenol A toxicity on oyster (Crassostrea angulata) gonads as revealed by label-free quantitative proteomics.

Bisphenol A (BPA) is widely used in industry, and is released in large amounts into the environment. BPA is a teratogen and an estrogen receptor agonist and negatively affects reproduction, particularly in aquatic animals, which is of concern for the aquaculture industry. Although there is a large body of literature on the mechanisms that underlie BPA disruption and the effects of different toxicities on invertebrate reproduction, many of the mechanisms involved in invertebrate responses to BPA remain unknown. In this study, we investigated the effects of BPA on the reproduction of female and male oysters (Crassostrea angulata), and measured BPA bioaccumulation, the gonad-somatic index (GSI), and gonadal protein profiles in oysters exposed to BPA. Compared to controls, approximately 160-times more BPA accumulated in the gonads of male and female oysters after exposure to 2 mg L-1 BPA for 16 days. Gonadal development was negatively affected in males, but was accelerated in females when exposed to BPA, based on GSI analysis and a visual inspection of histological sections of the gonads. BPA exposure induced the differential expression of many important proteins such as vitellogenin, periostin, phosphoglucomutase, collagen alpha-1(XII) chain, and zinc transporter 9, which are involved in energy metabolism, oxidative stress, gene transcription regulation, the vitellogenin interaction network, and zinc transportation. A functional analysis of these proteins indicated that BPA has different effects on gonadal development in male and female oysters.