Embryonic Development of a Tardigrade

沙丁鱼是一门鲜为人知的动物，它们的系统发育地位使它们成为研究发育如何进化的理想类群。迟滞是一个分支的成员，该分支包括两种最广为人知的后生动物模式生物--果蝇和线虫。它们还分享了果蝇或线虫的一些关键特征，这些特征对发育生物学家很有用，包括节段式重复的身体单位和四肢，细胞数量很少，据报道是恒定的，以及光学透明的胚胎。尽管如此，人们对它们的发展知之甚少。关于迟缓发育的三项信息量最大的研究是在1930年之前发表的，几乎没有来自活胚胎的发育数据。例如，没有命运图，甚至没有基本的细胞谱系。戈尔茨坦实验室已经开始研究迟缓的胚胎发育。其目标是测试关于细胞谱系和细胞命运规范如何进化的假设，同时提供使迟滞成为研究发育进化的模型系统所需的基本信息。四维显微镜被用来追踪细胞谱系并生成命运图。用于激光消融线虫单个细胞的方法正在扩展到延迟性，以确定在指定细胞命运中发挥作用的细胞相互作用。这项工作的长期目标是帮助理解在模式生物中阐明的发育程序是如何进化成自然界中发现的形态多样性的。拟议活动产生的广泛影响(1)发现、理解、教学、培训、学习：这个研究项目将包括培训本科生进行科学研究，每个本科生将参加一次年度会议，展示他们的发现。(2)代表不足的群体：首席研究员是北卡罗来纳大学教堂山研究教育支持计划的教师导师，该计划支持来自代表不足的少数群体的学生获得研究经验并注册博士项目。(3)研究和教育基础设施：应要求，活胚胎显微镜方法将公开与其他实验室共享。(4)广泛传播：除了在科学期刊上发表成果外，还将建立一个迟缓发育电影的网页，类似于戈尔茨坦实验室广泛使用的线虫电影网页，供其他人免费使用。(5)社会效益：这项工作将有助于美国大学的研究和教育任务，任何引起广泛关注的成果也将在出版时通过北卡罗来纳大学教堂山的新闻服务传播。

0235658GoldsteinTardigrades are a little-studied phylum of animals whose phylogenetic position makes them an ideal group for studies of how development evolves. The tardigrades are members of a clade that includes two of the most well-understood metazoan model organisms, Drosophila and C. elegans. They also share some of the key features of Drosophila or C. elegans that are useful to developmental biologists, including segment-like repeating body units and limbs, a small and reportedly constant cell number, and optically clear embryos. Despite this, very little is known about their development. The three most informative studies of tardigrade development were published before 1930, and there exists almost no developmental data from live embryos. For example, there is no fate map, nor even a rudimentary cell lineage. The Goldstein lab has begun to study tardigrade embryonic development. The goal is to test hypotheses regarding how cell lineage and cell fate specification have evolved, while providing the basic information required to make tardigrades a model system for studying evolution of development. Four-dimensional microscopy is being used to trace cell lineages and generate a fate map. Methods used for laser-ablation of individual cells in C. elegans are being extended to tardigrades to identify cell interactions that play roles in specifying cell fates. The long-term goal of this work is to contribute toward understanding how the developmental programs elucidated in model organisms have evolved to produce the morphological diversity found in nature.Broader impacts resulting from the proposed activity (1) Discovery, understanding, teaching, training, learning: This research project will include training undergraduate students in scientific research, and each undergraduate student will attend an annual conference to present their findings. (2) Underrepresented groups: The principal investigator is a faculty mentor in UNC Chapel Hill's Research Education Support Program, which supports students from underrepresented minority groups to gain research experiences and to enroll in Ph.D. programs. (3) Research and education infrastructure: Live-embryo microscopy methods will be openly shared with other labs upon request. (4) Broad dissemination: As well as publishing results in scientific journals, a web page of films of tardigrade development will be constructed, similar to the Goldstein lab's widely-used C. elegans movies web page, for use as a freely-available educational material by others. (5) Benefits to society: This work will contribute to both the research and education missions of American universities, and any results of broad interest will also be disseminated at publication time through UNC Chapel Hill's news service.