Diet and thermal limits: eating for survival and fertility

气候变化增加了极端天气事件的频率。热浪可以杀死生物，但也可能通过损害生育能力增加灭绝风险。精子被认为对热特别敏感，雄性昆虫经常在低于致命温度的情况下变得不育。但生物体能做些什么来缓冲极端温度吗？最近的发现表明，值得注意的是，果蝇黑腹果蝇改变了它的饮食，以缓冲高温和寒冷。它会根据温度改变食物偏好，以获得让它更好生存的饮食脂质。具体地说，食用植物来源的脂肪有助于它在寒冷中生存，而食用酵母来源的脂肪有助于它在高温下生存。然而，我们不知道这种适应是否也存在于经历不同气候的其他物种中，也不知道饮食变化是否改善了温度压力下的繁殖性能和存活率。目的：总体目标是测试来自一系列自然气候的不同种类的果蝇是否使用饮食转换来在极端温度下生存和繁殖。具体目标是：1)测试温度介导的饮食转换在经历更大季节性温度范围的物种中更普遍的假设。2)测试饮食脂质是否会改变温度极端情况下雄性和雌性的生殖性能。新颖性和及时性：如果我们要预测生物多样性将如何应对气候变化，关于生物如何缓解极端温度的知识至关重要。饮食的作用相对来说还没有被探索，但有可能作为一种预防极端温度的措施。该项目将确定改变饮食是否是一种覆盖广泛气候范围的昆虫种类中普遍存在的应对温度的机制。该项目还将探索受精成功--物种持久性和性选择的关键因素--是否是等式的一部分。

Climate change increases the frequency of extreme weather events. Heatwaves can kill organisms, but may also increase extinction risk by harming fertility. Sperm are thought to be especially sensitive to heat, and male insects often become infertile at lower-than-fatal temperatures. But can organisms do anything to buffer against temperature extremes? Recent discoveries show that remarkably, the fruit fly Drosophila melanogaster, changes its diet to buffer against heat and cold. It switches its food preferences in response to temperature, to obtain dietary lipids that allow it to better survive. Specifically, eating plant-derived lipids helps it survive the cold, while eating yeast-derived lipids helps it survive the heat. However, we do not know whether this adaptation is also present in other species that experience different climates, nor whether dietary changes improve reproductive performance, as well as survival, under temperature stress.Objectives:The overall aim is to test whether different species of fruit flies, originating from a range of natural climates, use diet switches to survive and reproduce under temperature extremes. The specific objectives are:1) To test the hypothesis that temperature-mediated diet switches are more prevalent in species that experience bigger seasonal temperature ranges.2) To test whether dietary lipids alter the reproductive performance of males and females under temperature extremes.Novelty and Timeliness:Knowledge of how organisms mitigate against extreme temperatures is vital if we are to predict how biodiversity will respond to climate change. The role of diet relatively unexplored, but has the potential to act as a prophylactic against temperature extremes. This project will establish whether diet switching is a widespread temperature coping mechanism among a genus of insects, covering a wide climatic range. The project will also explore whether fertilisation success - a key factor in species' persistence and in sexual selection - is part of the equation.