Control of Size and Allometry: A Top-Down Approach

提案编号：ios -0744952提案名称：尺寸和异速控制：自上而下的方法本工作将研究调节身体部位比例大小的机制。身体各部位的相对尺寸与全身尺寸之间的关系称为异速生长。在一个动物分类群中，形态进化主要是通过异速生长的变化发生的。因此，了解身体各部分达到其绝对和相对尺寸的过程对于深入理解动物形态的发展和进化至关重要。该领域的大多数实验工作都集中在“自下而上”的研究上，即检查基因操作对最终尺寸的影响。我们所缺少的是对身体部位形成最终尺寸和形状的过程的理解。本文提出的“自顶向下”方法将通过研究局部细胞增殖、细胞扩大和细胞死亡如何决定最终大小和形状来重建身体部位达到最终大小的途径。拟议的工作将集中在昆虫翅膀的发展，其中细胞研究特别容易处理。拟议的工作将发现基因和营养引起的绝对和相对翅膀大小和形状的差异是否由于细胞大小或细胞数量的差异，局部细胞分裂速率和/或细胞分裂时间的差异，以及细胞死亡的模式。这项工作的意义在于，它将开始一步一步地确定遗传变化导致大小和形状变化的潜在过程。本文提出的理解大小和形状的方法一般适用于其他身体部位和其他物种，是对分子遗传学方法的重要补充。本科生的教育一直是Nijhout博士研究计划的一个组成部分。在过去的5年里，本科生的研究在同行评议的文献中发表了7篇论文。Nijhout博士在达勒姆地区的不同地点定期给公众做讲座，介绍他的国家科学基金会资助的研究。

Name: H. Frederik NijhoutProposal #: IOS-0744952Proposal Title: Control of Size and Allometry: A Top-Down ApproachIntellectual Merit This work will study the mechanisms that regulate the proportional sizes of body parts. The relationship between the relative sizes of body parts and overall body size is called allometry. Within a taxonomic group of animals, morphological evolution occurs primarily by changes in allometry. Hence understanding the processes by which body parts achieve their absolute and relative sizes is critical for a deep understanding of the development and evolution of animal form. Most experimental work in this field has focused on "bottom up" studies that examine the effects of the genetic manipulation on the final size. What is missing is an understanding of the processes by which body parts get to their exact final size and shape. The "top down" approach proposed here will reconstruct the pathways by which body parts achieved their final size by studying how local cell proliferation, cell enlargement, and cell death act to determine final size and shape. The proposed work will focus on the development of the wings of insects where cellular studies are particularly tractable. The proposed work will discover whether genetically- and nutritionally-caused differences in absolute and relative wing sizes and shapes are due to differences in cell size or cell number, in localized rate of cell divisions and/or the timing of cell divisions, and patterned cell death. The significance of this work is that it will begin to identify, step by step, the underlying processes by which genetic changes lead to changes in size and shape. Broader Impacts The approach to understanding size and shape proposed here is generally applicable to other body parts and other species and is an essential complement to molecular-genetic approaches. The education of undergraduate students has always been an integral part of Dr. Nijhout's research program. The research of undergraduate students has resulted in 7 publications in the peer-reviewed literature in the past 5 years. Dr. Nijhout gives regular public lay person's lectures about his NSF-funded research at various venues in the Durham area.