While animal bodies are typically bilaterally symmetric on the outside, the internal organs nearly always show an invariant left-right (LR) asymmetry. In comparison, snails are both internally and externally LR asymmetric, outwardly obvious in the shell coiling direction, or chirality. Although some species of snail are naturally variable for chirality, sinistral individuals occur very rarely in most species. The developmental and genetic basis of these rare mirror-imaged individuals remains mysterious. To resolve this issue, the finding of a 'one in a million' sinistral garden snail called 'Jeremy' was used to recruit citizen scientists to find further sinistral snails. These snails were then bred together to understand whether their occurrence is due an inherited condition. The combined evidence shows that rare sinistral garden snails are not usually produced due to a major effect maternal Mendelian locus. Instead, they are likely mainly produced by a developmental accident. This finding has relevance to understanding the common factors that define cellular and organismal LR asymmetry, and the origin of rare reversed individuals in other animal groups that exhibit nearly invariant LR asymmetry.

中文翻译：

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互联网的“无聊”反映了稀有镜像蜗牛的起源。

虽然动物体通常在外部是两侧对称的，但内部器官几乎总是显示出不变的左右（LR）不对称性。相比之下，蜗牛在内部和外部均为LR不对称，在壳的卷曲方向或手性上向外明显。尽管某些蜗牛的手性是自然变化的，但在大多数物种中，鼻窦个体很少出现。这些罕见的镜像个体的发育和遗传基础仍然是神秘的。为了解决这个问题，人们发现了一个名为“杰里米”的“百万分之一”的鼻祖蜗牛来招募公民科学家，以寻找更多的鼻祖蜗牛。然后将这些蜗牛饲养在一起，以了解它们的发生是否是由于遗传引起的。综合证据表明，由于产妇孟德尔基因座的主要影响，通常不会产生稀有的鼻窦蜗牛。取而代之的是，它们很可能主要是由发展事故造成的。这一发现与理解定义细胞和机体LR不对称性的共同因素以及其他动物群体中表现出几乎不变的LR不对称性的稀有逆转个体的起源有关。