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。尽管如此，它们还是主宰着温带和极地生态系统，忍受着有可能结冰的温度。耐寒节肢动物的策略通常分为耐冻（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繁荣的机制。我建议解决低温生理学中的三个主要未知数：1）一些昆虫如何在冷冻固体中生存，2）昆虫如何保护它们的细胞免受非冰冻的寒冷，以及3）尽管冬季充满挑战，但蛛形纲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识别与春季田间蟋蟀的抗冻性相关的分子。然后，我将使用各种方法来操纵这些分子，以确定哪些分子对冷冻后的生存能力有影响。 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，这将揭示生存内部冰形成的细胞机制。 第二，我将使用基因和冷冻保护剂的操作在防冻科罗拉多马铃薯甲虫，以确定冷冻保护剂如何保护整个甲虫，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保存的结果。 第三，我将首次确定北极伪蝎和蜘蛛如何忍受极端的冬季环境。 为了做到这一点，我将首先测量耐寒性和相关分子在冬季收集的伪蝎在育空地区。 第二，我将在加拿大高北极研究站启动一项研究蜘蛛的长期计划，有可能确定新的耐寒机制。 我提出的计划将培养至少7名博士，7名硕士和5名本科生在这个授予周期的技能，从基本的昆虫学和实验室技能，生物信息学和北极的领导。

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.