Effects of Environmental Pollution on Molluscan Endocrinology

由环境污染引起的内分泌干扰已知会导致软体动物的生殖、发育和生长异常。例如，软体动物接触异生物化学品（如三丁基锡化合物）已被证明会导致雌性腹足动物的雄性化（即性畸变）。然而，许多内分泌紊乱的潜在机制，包括性畸变，尚未得到充分理解，由于缺乏知识的软体动物内分泌。例如，有一种假设认为脊椎动物型类固醇（如睾酮）是软体动物从头生物合成的一部分。然而，越来越多的证据表明软体动物并不具备产生脊椎动物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鉴定出了其他基因的同源物，例如在脊椎动物和植物类固醇合成中起重要作用的5-α还原酶。淡水腹足类生物光滑双脐螺（Biomphalaria glabrata）中5-α还原酶的化学破坏，导致了一种强烈的表型反应，破坏了正常发育，这表明缺乏机械理解如何导致化学品（如药物）对软体动物生理学产生不可预测的影响。该项目旨在通过将生态毒理学体内方法与分子/组学方法相结合，解决软体动物内分泌过程中的关键空白。扩大我们对软体动物内分泌学的理解，从而可以实现适当的化学调节和软体动物保护措施。

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.