Metabolic fuel selection: Exercise and cold exposure

这项研究涉及动物在寒冷中生存和进行长距离迁徙的能力。第一个项目调查鱼类如何应对温度变化和多氯联苯等环境污染物。冷血动物必须能够改变细胞膜，以确保在它们的体温波动时保持正常的新陈代谢。由于许多多氯联苯积聚在细胞膜内，因此了解这些毒素是否会干扰在适应不同温度期间发生的挽救生命的细胞膜变化尤为重要。 第二个项目调查候鸟在寒冷暴露和耐力训练期间如何管理它们的能量储备。长途候鸟在非常寒冷的环境中生存，并在迁徙过程中利用脂肪储备，具有非凡的能力。然而，这些令人惊叹的运动员用来应对寒冷和马不停蹄地旅行数千公里的机制还没有阐明。我们将确定加拿大鹅如何在冬天保护它们身体未隔热的部分免受冰冻。我们将进行实验，测试它们是否定期向腿上注入温血，并在脚上放置抗冻蛋白，以在寒冷中生存。新孵化的鹅通常会在它们的母亲身上留下印记，但它们也可以在人类代孕父母身上这样做。我们将在一架超轻型参数飞行器的飞行员身上印上小鹅，并训练它们自由飞行。经过训练的成年鹅(4公斤)将被安装一个150克重的背包，其中包含一个能够监测它们使用代谢燃料的自动化设备。这个机器人将第一次帮助我们测量它们在飞行过程中如何以创纪录的速度将能量从脂肪储备转移到工作肌肉。这项研究对以下方面具有重要意义：1)了解鱼类在环境污染物存在的情况下将如何应对全球变暖；2)制定野生动物保护的新政策，以帮助濒危候鸟物种管理能源；3)寻找新的方法来提高人类运动员的成绩。

This research deals with the ability of animals to survive in the cold and to perform long-distance migrations. The first project investigates how fish cope with changes in temperature and environmental contaminants like PCBs. Cold-blooded animals must be able to modify cell membranes to ensure the maintenance of normal metabolism as their body temperature fluctuates. Because many PCBs accumulate within membranes, it is particularly important to know whether these toxins interfere with the life-saving changes in membranes taking place during acclimation to different temperatures. The second project investigates how migrant birds manage their energy reserves during cold exposure and endurance exercise. Long-distance migrant birds have a remarkable ability to survive in very cold environments and to use fat stores during locomotion. However, the mechanisms used by these amazing athletes to cope with cold and to travel non-stop for thousands of kilometers have not been elucidated. We will determine how Canada geese protect uninsulated parts of their body from freezing in the winter. We will carry out experiments to test whether they flood their legs with warm blood at regular intervals and possess antifreeze proteins in their feet to survive in the cold. Newly hatched geese normally imprint on their mother, but they can also do so on a human surrogate parent. We will imprint young geese on the pilot of an ultralight paramotor and train them to follow it in free flight. Trained adult geese (4 kg) will be fitted with a 150-g backpack containing an automated device able to monitor their use of metabolic fuels. For the first time, this robot will help us to measure how they transfer energy from fat reserves to working muscles at record rates during flight. This research has significant implications for: 1) understanding how fish will cope with global warming in the presence of environmental contaminants, 2) formulating new policies for wildlife conservation to help endangered migrant bird species to manage energy, and 3) finding new ways to improve the performance of human athletes.