Biology of Arthropods at low temperatures

节肢动物是最成功的陆生动物，尽管它们无法保持稳定的体温。然而，它们主宰着温带和极地生态系统，在有结冰风险的地方也能忍受温度。耐寒节肢动物采用的策略一般分为耐寒（抵御内部结冰）和避冻（在低温下生存，但被内部结冰杀死）。我的长期目标是了解一些节肢动物在寒冷环境中生存和茁壮成长的机制。我建议解决低温生理学中三个主要的未知问题：1)一些昆虫如何在冰冻固体中生存，2)昆虫如何保护它们的细胞免受非冰冻的寒冷，以及3)尽管冬天充满挑战，但蜘蛛类动物如何在北极茁壮成长。在我的第一个目标中，我将使用转录组学和代谢组学来鉴定与春田蟋蟀耐寒性相关的分子。然后，我将使用各种方法来操纵这些分子，以确定哪些分子对在冷冻中存活的能力有致病影响。我还将缩小这项工作的范围，首次探索细胞对冰形成的反应。总之，这将揭示存活的内部冰形成的细胞机制。其次，我将在科罗拉多马铃薯甲虫中使用基因操作和冷冻保护剂，以确定冷冻保护剂如何保护整个甲虫和细胞内部免受低温造成的损害。这将产生广泛适用于昆虫耐寒性和哺乳动物细胞和组织的保存的结果。第三，我将首次确定，北极的假蝎子和蜘蛛是如何忍受极端的冬季环境的。为此，我将首先测量育空地区冬季采集的假蝎子的耐寒性和相关分子。其次，我将在加拿大高北极研究站启动一项长期研究蜘蛛的计划，有可能确定新的耐寒机制。我提议的项目将在这个授予周期内培养至少7名博士、7名硕士和5名本科生，技能范围从基本的昆虫学和实验室技能到生物信息学和北极领导力。

Arthropods are the most successful terrestrial animals, despite their inability to maintain a stable body temperature. Nevertheless, they dominate temperate and polar ecosystems, tolerating temperatures where they risk freezing. Strategies used by cold-tolerant arthropods are generally divided into freeze tolerance (withstand internal ice formation) and freeze avoidance (survive low temperatures, but killed by internal ice formation). My long term objective is to understand the mechanisms that allow some arthropods to survive and thrive in cold environments. I propose to address three major unknowns in low temperature physiology: 1) how some insects survive being frozen solid, 2) how insects protect their cells from non-freezing cold, and 3) how arachnids thrive in the Arctic in spite of challenging winters.In my first objective, I will use transcriptomics and metabolomics to identify the molecules associated with freeze tolerance in the spring field cricket. I will then use a variety of methods to manipulate these molecules to identify which ones have a causative impact on the ability to survive freezing. I will also narrow this work down to explore, for the first time, the cellular responses to ice formation. Together, this will reveal the cellular mechanisms of surviving internal ice formation.Second, I will use manipulations of genes and cryoprotectants in the freeze-avoidant Colorado Potato Beetle, to determine how cryoprotectants protect both the whole beetle, and the interior of cells, against damage caused at low temperatures. This will yield results broadly applicable to both insect cold tolerance and preservation of mammalian cells and tissues.Third, I will determine, for the first time, how Arctic pseudoscorpions and spiders tolerate their extreme winter environments. To do this, I will first measure cold tolerance and associated molecules in winter-collected pseudoscorpions in the Yukon. Second, I will initiate a long-term programme studying spiders at the Canadian High Arctic Research Station, with the possibility of identifying novel cold tolerance mechanisms.My proposed programme will train at least seven PhD, seven MSc, and five undergraduate students in this granting cycle in skills ranging from basic entomology and laboratory skills to bioinformatics and Arctic leadership.