Effects of Environmental Pollution on Molluscan Endocrinology

环境污染引起的内分泌紊乱会导致软体动物的繁殖、发育和生长异常。例如，软体动物暴露在外来化学物质(如TBT)中已被证明会导致雌性腹足动物的男性化(即性畸变)。然而，由于对软体动物内分泌学知识的缺乏，许多内分泌紊乱的潜在机制，包括性畸变，还没有完全被理解。例如，有一种假设认为脊椎动物类型的类固醇(如睾酮)是软体动物从头合成的一部分。然而，越来越多的证据表明，软体动物并不拥有产生脊椎动物类型性激素所需的所有类固醇生成酶。相反，在软体动物基因组中已经发现了其他基因的同源基因，如在脊椎动物和植物类固醇合成中发挥重要作用的5-α还原酶。对淡水腹足动物光滑生物5-α还原酶的化学破坏会引起强烈的表型反应，扰乱正常发育，这表明缺乏对机制的了解可以导致化学物质，如药物，对软体动物生理产生不可预测的影响。该项目旨在通过将活体生态毒理学方法与分子/组学方法相结合，解决软体动物内分泌过程中的关键空白。因此，扩大我们对软体动物内分泌学的理解可以实现适当的化学调节和软体动物保护实践。

Endocrine disruption, caused by environmental pollution, is known to result in abnormalities in the reproduction, development and growth of Molluscs. For example, exposure of molluscs to xenobiotic chemicals (e.g. TBT) has been shown to cause the masculinisation (i.e. imposex) of female gastropods. However, the underlying mechanisms of many endocrine disruption disorders, including imposex, have yet to be fully understood due to a deficit of knowledge of molluscan endocrinology. For example, there has been an assumption that vertebrate-type steroids (e.g. testosterone) are part of de novo biosynthesis in molluscs. However, there is a growing body of evidence indicating molluscs do not possess all the steroidogenic enzymes needed to produce vertebrate-type sex hormones. In contrast, homologues of other gene, such as 5-alpha reductase, which plays an important role in vertebrate and plant steroidogenesis, have been identified in mollusc genomes. Chemical disruption of 5-alpha reductase enzymes in a freshwater gastropod, Biomphalaria glabrata, elicits a strong phenotypic response disrupting normal development, Ddemonstrating how a lack mechanistic understanding can result in chemicals, such as pharmaceuticals, having unpredictable impacts on mollusc physiology. This project aims to address critical gaps in the endocrinological processes of molluscs, by combining ecotoxicological in vivo methods with molecular/omics approaches. Expanding our understanding of molluscan endocrinology can thus allow appropriate chemical regulation and molluscan conservation practices to be achieved.