Identification of regulatory genes and signalling pathways that coordinate the fabrication of the gastropod shell

生物矿化能力的进化是复杂动物生命兴起的分水岭事件之一。然而，我们对这种能力在任何动物谱系中最初是如何进化的了解几乎是不存在的。软体动物（第二大动物门）在现存（和灭绝）物种的数量、它们所展示的身体形式的多样性以及它们所占据的栖息地范围方面都取得了巨大的进化成功。这种成功在很大程度上可以归因于壳的进化可塑性。尽管软体动物外壳呈现出惊人的形态多样性，但它的构造方式被认为具有共同的进化起源，而这一点尚不清楚。在本文中，我们将通过研究腹足类动物构建其外壳的分子机制来解决这个问题，并为理解软体动物外壳的进化做出重大贡献。我们的具体目标是：(1)利用转录组学和基因组资源以及全株原位杂交，确定与停滞淋巴细胞壳形成起始相关的信号通路和调控分子；(2)与目标1平行，通过药物方法筛选在壳腺形成中起作用的信号通路；(3)开发一种功能分析，使我们能够具体表征目标1和/或2确定的感兴趣基因的功能。

The evolution of the ability to biomineralise was one of the watershed events in the rise of complex animal life. However our understanding of how this ability first evolved in any animal lineage is almost non-existent. Molluscs (the second largest animal phylum) have enjoyed great evolutionary success in terms of the number of extant (and extinct) species, the diversity of body forms that they display and the range of habitats that they occupy. Much of this success could be attributed to the evolutionary plasticity of the shell. Despite the spectacular diversity of morphologies that the molluscan shell exhibits, the way in which it is constructed is believed to have common evolutionary origins that are not understood. In this proposal we will address this problem and significantly contribute to an understanding of molluscan shell evolution by studying the molecular mechanisms employed by a gastropod to construct its shell. Our specific objectives are to (1) identify signalling pathways and regulatory molecules associated with the initiation of shell formation in Lymnaea stagnalis using transcriptomic and genomic resources and whole mount in situ hybridisation; (2) in parallel with objective 1 to screen signalling pathways for a role in shell gland formation via a pharmaceutical approach; (3) to develop a functional assay that will allow us to specifically characterise the function of genes of interest identified by objectives 1 and/or 2.