DISSERTATION RESEARCH: Small RNA regulation and the evolution of extreme anoxia tolerance

这个项目将追踪脊椎动物低氧耐受性的进化过程。这项研究可能揭示了支持缺氧耐受性的新的细胞机制，这可能会改变我们对心脏病发作和中风的预防和治疗。没有足够的血液流向心脏和大脑，人类和大多数其他脊椎动物只能存活几分钟。血流量的减少会阻碍氧气的供应，并迅速导致组织缺氧或缺氧。然而，有少数脊椎动物可以在完全缺氧的情况下存活数月。本项目检查并比较了来自每个主要脊椎动物群体的物种的缺氧耐受基因的表达。该项目还将促进国际科学合作，并提供一名女博士候选人和本科生的培训。此外，研究结果将提交给圣玛丽大学科学研究方法课程。s Academy是当地的一所女子高中。为了研究小RNA的表达和缺氧耐受性的进化，我们将在肩章鲨、鲫鱼、年生鳉鱼胚胎、豹纹蛙和淡水龟中检测小RNA的表达。这些物种分别代表了最耐缺氧的软骨鱼、硬骨鱼、两栖动物和爬行动物。这项研究验证了一个假设，即常见的小rna支持这些少数最耐受性的脊椎动物的缺氧耐受性，表明这一生活史特征的趋同进化。已知的低氧反应和新的低氧反应小rna最近被发现在耐缺氧的一年生泥鳅Austrofundulus limnaeus。本项目将通过比较耐缺氧脊椎动物物种中的小rna，来测试它们在耐缺氧进化和维持中的作用。每个物种将暴露于缺氧中并在其生态相关温度下恢复，并在3个时间点采样：a)缺氧前；b)缺氧时；c)在缺氧后的有氧恢复期间。具体的暴露间隔是根据每个物种的最大缺氧耐受性来设定的。总RNA将从脑组织中提取，因为大脑是对缺氧最敏感的器官，并准备进行小RNA测序，并比较表达模式。

This project will trace the evolution of low-oxygen tolerance in vertebrates. The study may reveal novel cellular mechanisms underpinning anoxia tolerance, which may transform our prevention and treatment of heart attack and stroke. Humans, and most other vertebrates, can survive for only a few minutes without adequate blood flow to the heart and brain. Loss of blood flow blocks the supply of oxygen, and quickly leads to tissue anoxia, or lack of oxygen. Yet, there are a handful of vertebrates that can survive for months in the complete absence of oxygen. This project examines and compares the expression of genes involved in anoxia tolerance of species from each major vertebrate group. The project will also promote international scientific collaboration and provide training of a female Ph.D. candidate and undergraduate student. Additionally, research findings will be presented to a Science Research Methods class at St. Mary?s Academy, a local all-girls high school.To study small RNA expression and the evolution of anoxia tolerance, small RNA expression will be examined in the epaulette shark, crucian carp, annual killifish embryos, leopard frog, and freshwater turtles. These species represent the most anoxia-tolerant cartilaginous fish, bony fishes, amphibians and reptiles, respectively. This research tests the hypothesis that common small RNAs support the anoxia tolerance of these few most tolerant vertebrates, indicating a convergent evolution of the life history trait. Known hypoxia-responsive and novel anoxia-responsive small RNAs were recently identified in the anoxia tolerant annual killifish Austrofundulus limnaeus. This project will test the role of small RNAs in the evolution and maintenance of anoxia tolerance by comparing them among anoxia-tolerant vertebrate species. Each species will be exposed to anoxia and recovery at its ecologically relevant temperature and sampled at 3 time points: A.) prior to anoxia; B.) during anoxia; C.) during aerobic recovery following anoxia. The specific exposure intervals are set based on the maximal anoxia tolerance of each species. Total RNA will be extracted from brain tissue, since the brain is the most anoxia-sensitive organ, and prepared for small RNA sequencing, and expression patterns will be compared.