Temporal and spatial stress tolerance variation in Belgica antarctica

Environmental conditions are the major drivers of species distribution, and terrestrial Antarctica arguably presents the most dramatic challenges for its inhabitants. Many animals rely on acclimation to enhance their stress tolerance to face unfavorable conditions. Some animals can also rely on their phenotypic plasticity to respond to these unfavorable conditions without the need to slowly experience increasing levels of stress to enhance their stress tolerance (i.e., acclimate). Belgica antarctica can rely on both types of strategies, but since they evolved to live in a habitat with such dramatic environmental changes as Antarctica, they are very sensitive to any type of stress (e.g., a sudden drop in temperature, or a bout of high-speed wind). Studying the extent to which B. antarctica rely on each of these strategies to survive and how environmental variation can shape this species’ biology across distinct populations (i.e., that might experience distinct selective pressures) is important to help us better understand how polyextremophiles adapt and evolve while inhabiting extreme environments. This project focused on studying freeze tolerance in B. antarctica populations populations within Cormorant Island that inhabited three distinct microhabitats over the course of the summer season (January-March).环境条件是决定物种分布的核心驱动因素，而南极陆地生境无疑为其栖息生物带来了最为严苛的生存挑战。许多动物会通过生理驯化（acclimation）提升应激耐受能力，以应对不利环境条件。部分动物还可借助表型可塑性（phenotypic plasticity）响应此类不利环境，无需通过逐步暴露于递增程度的应激中来提升应激耐受能力（即无需驯化）。南极摇蚊（Belgica antarctica）可同时依托这两种策略生存，但由于其演化适配了南极这类环境剧变剧烈的生境，它们对各类应激均极为敏感（例如温度骤降或强风突袭）。研究南极摇蚊依赖每种策略生存的程度，以及环境变异如何塑造不同种群（即可能面临不同选择压力的种群）的生物学特征，有助于我们更深入理解多极端耐受生物（polyextremophiles）在极端环境中适应与演化的机制。本研究聚焦于夏季（1月至3月）期间，栖息于科莫兰特岛（Cormorant Island）三种不同微生境的南极摇蚊种群的冻耐受性。