School for the Environment, University of Massachusetts Boston, Boston, MA, USA.
Faculty of Medicine, Health and Life Sciences, Swansea University, Swansea, SA2 8PP, Wales, UK.
Sci Rep. 2024 Oct 12;14(1):23890. doi: 10.1038/s41598-024-74212-y.
Mollusks are the second most diverse animal phylum, yet little is known about their endocrinology or how they respond to endocrine disrupting compound (EDC) pollution. Characteristic effects of endocrine disruption are reproductive impairment, skewed sex ratios, development of opposite sex characteristics, and population decline. However, whether classical vertebrate EDCs, such as steroid hormone-like chemicals and inhibitors of steroidogenesis, exert effects on mollusks is controversial. In the blue mussel, Mytilus edulis, EDC exposure is correlated with feminized sex ratios in wild and laboratory mussels, but sex reversal has not been confirmed. Here, we describe a non-destructive qPCR assay to identify the sex of M. edulis allowing identification of males and females prior to experimentation. We exposed male mussels to 17α-ethinylestradiol and female mussels to ketoconazole, EDCs that mimic vertebrate steroid hormones or inhibit their biosynthesis. Both chemicals changed the sex of individual mussels, interfered with gonadal development, and disrupted gene expression of the sex differentiation pathway. Impacts from ketoconazole treatment, including changes in steroid levels, confirmed a role for steroidogenesis and steroid-like hormones in mollusk endocrinology. The present study expands the possibilities for laboratory and field monitoring of mollusk species and provides key insights into endocrine disruption and sexual differentiation in bivalves.
软体动物是第二大最多样化的动物门，然而，人们对它们的内分泌学或它们对内分泌干扰化合物 (EDC) 污染的反应知之甚少。内分泌干扰的典型影响是生殖损伤、性别比例偏斜、相反性特征的发育和种群减少。然而，经典的脊椎动物 EDC，如类固醇激素样化学物质和类固醇生成抑制剂，是否对软体动物产生影响仍存在争议。在贻贝中，Mytilus edulis，EDC 暴露与野生和实验室贻贝中雌性比例的女性化有关，但尚未证实性别反转。在这里，我们描述了一种非破坏性的 qPCR 测定法来识别 M. edulis 的性别，允许在实验前识别雄性和雌性。我们将雄性贻贝暴露于 17α-乙炔雌二醇和雌性贻贝暴露于酮康唑，这两种化学物质模拟脊椎动物类固醇激素或抑制其生物合成。这两种化学物质都改变了个别贻贝的性别，干扰了性腺发育，并破坏了性别分化途径的基因表达。酮康唑处理的影响，包括类固醇水平的变化，证实了类固醇生成和类固醇样激素在软体动物内分泌学中的作用。本研究扩展了实验室和野外监测软体动物物种的可能性，并为贝类内分泌干扰和性别分化提供了关键的见解。
