This is a critical review of what we know so far about the evolution of metallothioneins (MTs) in Gastropoda (snails, whelks, limpets and slugs), an important class of molluscs with over 90,000 known species. Particular attention will be paid to the evolution of snail MTs in relation to the role of some metallic trace elements (cadmium, zinc and copper) and their interaction with MTs, also compared to MTs from other animal phyla. The article also highlights the important distinction, yet close relationship, between the structural and metal-selective binding properties of gastropod MTs and their physiological functionality in the living organism. It appears that in the course of the evolution of Gastropoda, the trace metal cadmium (Cd) must have played an essential role in the development of Cd-selective MT variants. It is shown how the structures and Cd-selective binding properties in the basal gastropod clades have evolved by testing and optimizing different combinations of ancestral and novel MT domains, and how some of these domains have become established in modern and recent gastropod clades. In this context, the question of how adaptation to new habitats and lifestyles has affected the original MT traits in different gastropod lineages will also be addressed. The 3D structures and their metal binding preferences will be highlighted exemplarily in MTs of modern littorinid and helicid snails. Finally, the importance of the different metal requirements and pathways in snail tissues and cells for the shaping and functionality of the respective MT isoforms will be shown.

这是对迄今为止我们所了解的腹足纲（蜗牛、海螺、帽贝和蛞蝓）中金属硫蛋白 (MT) 进化的批判性回顾，腹足纲是一类重要的软体动物，已知物种超过 90,000 种。将特别关注蜗牛 MT 的进化与某些金属微量元素（镉、锌和铜）的作用及其与 MT 的相互作用，以及与其他动物门的 MT 的比较。该文章还强调了腹足动物 MT 的结构和金属选择性结合特性与其在生物体中的生理功能之间的重要区别和密切关系。看来，在腹足纲的进化过程中，痕量金属镉（Cd）在 Cd 选择性 MT 变体的发展中发挥了重要作用。通过测试和优化祖先和新的 MT 结构域的不同组合，展示了基础腹足动物进化枝中的结构和 Cd 选择性结合特性是如何进化的，以及其中一些结构域是如何在现代和最近的腹足动物进化枝中建立的。在这种背景下，适应新的栖息地和生活方式如何影响不同腹足动物谱系的原始MT特征的问题也将得到解决。3D 结构及其金属结合偏好将在现代 littorinid 和 helicid 蜗牛的 MT 中突出显示。最后，将展示蜗牛组织和细胞中不同金属需求和途径对于相应 MT 亚型的形成和功能的重要性。