Subventions et des contributions :

Subvention ou bourse octroyée s'appliquant à plus d'un exercice financier. (2017-2018 à 2022-2023)

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.