The effects of bisphenol S exposure on the growth, physiological and biochemical indices, and ecdysteroid receptor gene expression in red swamp crayfish, Procambarus clarkii

The experiment was conducted to investigate the effects of Bisphenol S (BPS) on growth, physiological and biochemical indices, and the expression of ecdysteroid receptor (ECR) of the red swamp crayfish (Procambarus clarkii). The gene encoding ECR was isolated from red swamp crayfish by homologous cloning and rapid amplification of cDNA ends (RACE). The ECR transcripts were 1757 bp long and encoded proteins of 576 amino acids. The quantitative real-time PCR (qRT-PCR) analysis showed that the ECR gene was expressed in various tissues under normal conditions, and the highest level was observed in the ovary and the lowest level was observed in the muscle (P < 0.05). Then, the experiment was designed with four different BPS concentrations (0, 1, 10, and 100 mu g/L), BPS exposure for 14 days, three parallel groups, and a total of 240 red swamp crayfish. At 100 mu g/L BPS, the survival rate, weight gain rate, and relative length rate were decreased significantly (P < 0.05). Malonaldehyde (MDA) content reached the highest level at 100 mu g/L BPS. When BPS concentration was higher than 10 mu g/L, the activities of superoxide dismutase (SOD) and catalase (CAT) were significantly lower than those of the control group (P < 0.05). The expression levels of the ECR gene in ovary, intestinal, gill, and hepatopancreas tissues were significantly increased after BPS exposure (P < 0.05). The ECR gene expression in ovaries and Y-organs was significantly higher than other groups in 10 mu g/L BPS (P < 0.05). The expressions of the tumor necrosis factor -alpha (TNF-alpha) and interleukin-6 (IL-6) genes in the hepatopancreas gradually increased, and the highest expression was observed exposed in 100 mu g/L BPS (P < 0.05). This research will provide novel insights into the health risk assessment of BPS in aquatic organisms.