DISSERTATION RESEARCH: Gastropod shells: A window into the developmental origins of diversity

这个项目研究了不同类型的外壳形状是如何在蜗牛胚胎中被编码的。动物的形态千差万别。这项研究解决了这样一个问题：产生这种多样性的发展机制是什么？蜗牛长期以来一直是研究生物形态的模型系统。它们的形状多种多样，但由于它们在数学上有规则的卷曲，所以很容易测量，自查尔斯·达尔文著名的环球航行以来，它们一直是一个主要的研究小组。达尔文研究动物形态的方法包括调查蜗牛丰富的化石记录（古生物学）的变化模式。现代发育生物学使用分子工具来了解基因如何决定蜗牛的形状。这个项目将确定遗传和环境的相互作用，这可能是古生物学中一个明显模式的基础，即从盘绕祖先到非盘绕壳的反复进化。研究人员将结合计算机成像技术、基因操作和古生物学，以提供无与伦比的精度来确定基因及其环境如何随着时间的推移塑造生物体。这项工作将产生更广泛的社会影响，部分原因是设计和实施了一个视觉扫盲讲习班。这次研讨会将提高研究人员和科学界理解和向公众传达复杂视觉信息的能力。讲习班的材料将在网上公布，以便更多地查阅。本项目研究了蜗牛壳形态的发育基础，以及在新兴的模式系统——普通滑靴壳（Crepidula fornicata）中从盘绕壳到非盘绕壳的转变。具体来说，它评估了一种假设，即一种名为decapentaplegic的蛋白质信号模式的简单修改可能是非卷曲壳进化模式的基础。其他外壳发育基因也将被评估是否有能力更普遍地影响外壳图案。受壳卷曲变化影响的遗传途径将在发育动物中被操纵，以分离它们对形态学的个体影响。这项工作需要详细的形态学数据。扫描电子显微镜将用于可视化扭转过程，并评估整个胚胎在遗传扰动下的形态变化。计算机断层扫描（CT扫描）将能够使用胚胎和外壳形状的三维形状分析，精度更高。将这些计算机辅助技术与分子技术相结合，将使人们对古生物模式是如何形成的有了新的认识。

This project investigates how different types of shell shapes are encoded in snail embryos. Animal form is marvelously varied. This study addresses the question: what are the developmental mechanisms that produce such diversity? Snails have long been a model system for studying biological form. They have diverse shapes but are easy to measure due to their mathematically regular coiling and have been a major study group since Charles Darwin's famous voyage around the world. Darwin's approach to the study of animal form included investigations of patterns of change in the snail-rich fossil record (paleontology). Modern developmental biology uses molecular tools to understand how genes determine snail form. This project will determine the genetic and environmental interactions that may underlie a conspicuous pattern in paleontology, the repeated evolution of non-coiled shells from coiled ancestors. The researchers will combine computer imaging technology, genetic manipulation and paleontology to provide unparalleled precision in determining how both genes and their environment shape an organism through time. Broader societal impacts will result from this work due in part to the design and implementation of a workshop on visual literacy. This workshop will improve the ability of the researchers and the scientific community to understand and convey complex visual information to the public. The workshop materials will be posted online for increased access. This project investigates the developmental basis of snail shell morphology and the transition from coiled to non-coiled shells in the emerging model system, the Common Slipper Shell (Crepidula fornicata). Specifically, it evaluates the hypothesis that simple modification in signaling patterns in a protein named decapentaplegic could be the basis for a pattern of non-coiled shell evolution. Other shell developmental genes also will be evaluated for the ability to affect shell patterning more generally. Genetic pathways influenced by changes in shell coiling will be manipulated in developing animals to isolate their individual effects on morphology. Detailed morphological data is required for this work. Scanning electron microscopy will be used to visualize the process of torsion and to assess morphological changes across the entire embryo in response to genetic perturbations. Computed tomography (CT scanning) will enable the use of 3-dimensional shape analysis of embryo and shell form with enhanced precision. The use of these computer-assisted technologies combined with molecular techniques will allow new insight into how paleontological patterns are formed.