Curvature as a Physical Determinant of Tissue Organization

这个项目将调查活组织的物理性质，这些性质在确定组织曲率方面很重要。PI将定量地确定有序组织中缺陷的数量和位置，并将发展一种可以与实验相比较的缺陷分布的力学理论。这是首次将组织曲率作为结构组织的决定因素的定量研究。在生物学和遗传学研究的最新进展的基础上，对生物的形态和形态发生的理解有了巨大的增长。然而，很少有人尝试通过量子力学来描述器官或组织的发育和结构。这项工作的结果将同样适用于所有显示出一定程度有序性的弯曲组织层，包括癌细胞腺泡，其形态对癌症的发展非常重要，以及桑拿期和囊胚期的胚胎发育。由于曲率导致有序度的限制，它可能在对称性破坏和极化中发挥作用，从而在胚胎的最早模式形成中发挥作用。描述机械力对细胞发育的直接影响将是在诊断和治疗(例如组织再生或癌症)的背景下更好地理解形态发生和组织形成的根本进展。数据采集将利用本科生的帮助以及通过伊利诺伊州现有的Bugscope项目延伸到高中生，从而通过一个视觉上令人着迷的跨学科项目与更广泛的公众联系起来。该项目将昆虫的眼睛作为有序组织结构的一个具体例子，因为复眼的极端规律性，复眼中的大量单眼(小眼)，以及结构可以相对容易地进行定量分析。使用扫描电子显微镜成像和共聚焦显微镜，目的是(I)确定小眼的完整微结构和(Ii)确定眼睛的宏观结构(全局形状和曲率)，以便(Iii)将小眼缺陷的数量和位置与曲面花纹表面的机械理论预测的小眼缺陷的数量和位置进行比较。现有的曲面缺陷放置理论(为固体物理学中的有限数量的例子而发展)将适用于昆虫眼睛中遇到的更一般的形状。数值模拟和分析理论都将得到发展。虽然成熟期和幼虫期的果蝇野生型和突变型眼睛将是主要焦点，但不同物种的昆虫眼睛大小和形状的差异是这项研究的一项财富。

This project will investigate the physical properties of living tissue that are important in determining the tissue curvature. The PI will quantitatively determining the number and location of defects in ordered tissues and will develop a mechanical theory of the defect distribution that can be compared with experiment. This constitutes the first quantitative study of tissue curvature as a determining factor of structural organization. Understanding of the morphology and morphogenesis of organisms has grown tremendously based on recent advances in biological and genetic research. Yet, few attempts have been undertaken to describe the development and structure of organs or tissues through quantitative mechanics. The results of this work will be equally applicable to all curved tissue layers that show a degree of order, including cancer cell acini, whose morphology is important for the development of cancer, as well as developing embryos in the morula and blastula stages. As curvature induces constraints on the degree of order, it may play a role in symmetry breaking and polarization, and thus in the earliest patterning of the embryo. Describing a direct influence of mechanical forces on cell development will be a fundamental advance towards a better understanding of morphogenesis and tissue formation in the context of both diagnostics and therapy, e.g. tissue regeneration or cancer. Data acquisition will employ the help of undergraduate students as well as outreach to high school students through the existing Bugscope project at Illinois, thus connecting with the broader public through a visually fascinating and interdisciplinary project.This project focuses on insect eyes as a concrete example of an ordered tissue structure, because of the extreme regularity of the compound eye, the large number of individual eyes (ommatidia) in the compound eye, and the relative ease with which the structure can be quantitatively analyzed. Using both SEM imaging and confocal microscopy, the goals are to (i) determine the complete microstructure of the ommatidia and (ii) determine the macrostructure (global shape and curvature) of the eye, in order to (iii) compare the number and position of ommatidial defects with those predicted by the mechanical theory of curved patterned surfaces. The existing theory of defect placement on curved surfaces (developed for a limited number of examples from solid state physics) will be adapted to the more general shapes encountered in insect eyes. Both numerical simulations and analytical theory will be developed. While Drosophila wild-type and mutant eyes in mature and pupal stages will be the main focus, the variety of insect eye sizes and shapes in different species is an asset to this study.