Liu Peipei, Miao Jingjing, Song Ying, Pan Luqing, Yin Pengfei
The Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Qingdao 266003, PR China.
The Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Qingdao 266003, PR China.
Aquat Toxicol. 2017 Dec;193:178-186. doi: 10.1016/j.aquatox.2017.10.022. Epub 2017 Oct 26.
The reported adverse effects of Polybrominated diphenyl ether (PBDE) congeners on gonadogenesis in fish may also occur in marine bivalves especially the burrowing species such as manila clam Ruditapes philippinarum. In this study, clams were exposed to BDE-47 for 25days at 0, 0.1 and 1μg/L. By using the water temperature control method, gonadal maturation from resting to ripe stage were observed successively in both the control and the treatment groups during 25days. The results showed that exposure to BDE-47 at concentration below 1μg/L did not delay the gonadogenesis process of the clam R. philippinarum, and no evidence of adverse effects of BDE-47 on clam gonadal histology was observed. However, exposure to 1μg/L BDE-47 caused significant decreases of haemolymph testosterone levels in both female and male clams at day 5 and day 15. The mRNA expression of 3β-HSD in females exposed to BDE-47 was significantly decreased at day 5, while mRNA expression of 17β-HSD and CYP17 was not significantly changed in either sex. Exposure to BDE-47 also resulted in up-regulation of the mRNA expression of vitellogenin (Vtg) in both sexes and spermatogenesis associated protein 4-homolog (SAP4) in males. These results suggest a potential contribution of BDE-47 to reproductive disruption in the manila clams, especially in males. This study demonstrates the promising utility of water temperature control method in conjunction with histological endpoints and biomarkers such as mRNA levels of Vtg in determining the reproductive disturbances caused by EDCs on bivalves.
多溴二苯醚（PBDE）同系物对鱼类性腺发育的不良影响也可能发生在海洋双壳贝类中，尤其是穴居物种，如菲律宾蛤仔（Ruditapes philippinarum）。在本研究中，将蛤仔暴露于浓度为0、0.1和1μg/L的BDE-47中25天。通过水温控制方法，在25天内，对照组和处理组均相继观察到性腺从静止期到成熟期的成熟过程。结果表明，暴露于浓度低于1μg/L的BDE-47不会延迟菲律宾蛤仔的性腺发育过程，且未观察到BDE-47对蛤仔性腺组织学有不良影响的证据。然而，暴露于1μg/L的BDE-47在第5天和第15天导致雌雄蛤仔血淋巴睾酮水平显著下降。暴露于BDE-47的雌性蛤仔在第5天3β-HSD的mRNA表达显著下降，而17β-HSD和CYP17的mRNA表达在两性中均无显著变化。暴露于BDE-47还导致两性中卵黄蛋白原（Vtg）的mRNA表达上调，雄性中精子发生相关蛋白4同源物（SAP4）的mRNA表达上调。这些结果表明BDE-47对菲律宾蛤仔的生殖干扰有潜在影响，尤其是对雄性。本研究证明了水温控制方法结合组织学终点和生物标志物（如Vtg的mRNA水平）在确定内分泌干扰物对双壳贝类生殖干扰方面的应用前景。
