Collaborative Research: Winter Survival Mechanisms and Adaptive Genetic Variation in an Antarctic Insect

极地地区是沙漠，不仅寒冷，而且缺乏免费水。南极昆虫有独特的生存机制，包括耐受冰冻和大范围脱水的能力，在失去70%的身体水分的情况下存活下来。如何做到这一点不仅对了解昆虫的季节性适应以及它们如何应对气候变化感兴趣，而且所采用的分子和生理机制可能为更一般的机制提供有价值的见解，这些机制可能被用于低温保存和长期储存人类组织和器官，用于移植和其他医疗应用。研究人员将研究负责从体内排出水分的蛋白质、细胞水平的后果，以及负责基因在不同种群之间的差异。该项目还将推动NSF向公众提供科学发现和培训新一代科学家的目标。每年，一名K-12教师将成为外地小组的成员，协助实地工作，并与学童及其教师进行接触。教育宣传工作包括在当地学校和全国教师会议上发表演讲，在网站上提供教案和播客，并继续在教育期刊上发表与这项研究有关的文章。此外，本科生和研究生将在研究项目的各个方面接受广泛的培训，并积累丰富的经验，包括发表科学论文和在全国会议上发表演讲。该项目侧重于破译使南极侏儒在干燥的极地环境中生存下来的环境压力和大部分身体水分损失的生理和分子机制。这种极端细菌是研究胁迫耐受性和局部地理适应机制的理想系统，它的基因组最近已经测序。该项目有三个重点领域：1)通过研究水通道蛋白(水通道蛋白)在脱水过程中的基因表达，评估水通道蛋白在体内快速排出水分中的作用；2)通过研究脱水过程中负责自噬的基因的表达，研究代谢抑制的机制和自噬(细胞成分的受控分解)作为应激耐受媒介的作用；以及3)利用该物种可用的基因组序列，结合采样种群及其栖息地的生理和环境数据，评估与应激耐受相关的种群结构、基因流动和生理特征的适应性变异。

Polar regions are deserts that are not only cold but also lack access to free water. Antarctic insects have unique survival mechanisms including the ability to tolerate freezing and extensive dehydration, surviving the loss of 70% of their body water. How this is done is of interest not only for understanding seasonal adaptations of insects and how they respond to climate change, but the molecular and physiological mechanisms employed may offer valuable insights into more general mechanisms that might be exploited for cryopreservation and long-term storage of human tissues and organs for transplantation and other medical applications. The investigators will study the proteins that are responsible for removing water from the body, cell level consequences of this, and how the responsible genes vary between populations. The project will also further the NSF goals of making scientific discoveries available to the general public and of training new generations of scientists. Each year a K-12 teacher will be a member of the field team and assist with fieldwork and outreach to school children and their teachers. Educational outreach efforts include presentations at local schools and national teacher meetings, providing lesson plans and podcasts on a website, and continuing to publish articles related to this research in education journals. In addition, undergraduate and graduate students will receive extensive training in all aspects of the research project with extended experiences that include publication of scientific papers and presentations at national meetings.This project focuses on deciphering the physiological and molecular mechanisms that enable the Antarctic midge Belgica antarctica to survive environmental stress and the loss of most of its body water in the desiccating polar environment. This extremophile is an ideal system for investigating mechanisms of stress tolerance and local geographic adaptations and its genome has recently been sequenced. This project has three focal areas: 1) Evaluating the role of aquaporins (water channel proteins) in the rapid removal of water from the body by studying expression of their genes during dehydration; 2) Investigating the mechanism of metabolic depression and the role of autophagy (controlled breakdown of cellular components) as a mediator of stress tolerance by studying expression of the genes responsible for autophagy during the dehydration process; and 3) Evaluating the population structure, gene flow, and adaptive variation in physiological traits associated with stress tolerance using a genetic approach that takes advantage of the genomic sequence available for this species coupled with physiological and environmental data from the sampled populations and their habitats.