In seeking to understand the establishment of left-right (LR) asymmetry, a limiting factor is that most animals are ordinarily invariant in their asymmetry, except when manipulated or mutated. It is therefore surprising that the wider scientific field does not appear to fully appreciate the remarkable fact that normal development in molluscs, especially snails, can flip between two chiral types without pathology. Here, I describe recent progress in understanding the evolution, development, and genetics of chiral variation in snails, and place it in context with other animals. I argue that the natural variation of snails is a crucial resource towards understanding the invariance in other animal groups and, ultimately, will be key in revealing the common factors that define cellular and organismal LR asymmetry.

中文翻译：

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弹壳！消除镜像软体动物中的LR不对称性。

在试图了解左右不对称性的建立过程中，一个限制因素是，大多数动物的不对称性通常不变，除非被操纵或突变。因此，令人惊讶的是，更广阔的科学领域似乎并未完全认识到软体动物，特别是蜗牛的正常发育可以在两种手性类型之间转移而没有病理的显着事实。在这里，我描述了了解蜗牛手性变异的进化，发展和遗传学方面的最新进展，并将其与其他动物进行了比较。我认为蜗牛的自然变异是了解其他动物种群不变性的关键资源，并且最终将成为揭示定义细胞和机体LR不对称性的共同因素的关键。