Understanding phenotypic integration from perspectives of allocation, risk and aging

生物进化的一个基本原则是，要想成功生存，投资必须达到最佳平衡，但在一个领域的大量投资需要在其他领域减少投资。功能（如生长和繁殖）不仅仅是争夺资源，它们之间的分配是一种激素调节的“策略”，可以根据环境进行调整。我们正在使用巨型转基因小鼠研究功能的全局调控，因为极大地夸大生长使我们能够看到其他功能与生长以及彼此之间的关系。特别令人感兴趣的是，这些老鼠的衰老速度显著加快。生长可能会从防止衰老的功能中转移资源（例如，介导抗逆性的途径）。我们正在通过开发膳食补充剂来了解更多，这些补充剂实际上可以减缓老鼠和昆虫的衰老速度。这些让我们看到衰老是如何缓慢实现的。我们最近发现，昆虫和甲壳类动物通过特定的气味来识别和避开受伤或死亡的亲戚。这种风险规避可以应用于控制各种害虫。此外，暴露在死亡气味中的蟋蟀不仅改变了它们的眼睛、翅膀和脊柱，而且寿命更长。食物限制是唯一已知的另一种能大大延长大多数动物寿命的方法。然而，如果受限制的动物能闻到食物，那么这些好处（包括抗压力）就消失了。因此，对死亡或饥荒风险的调整增加了寿命，这两者都与嗅觉有关。寿命的延长通常与抗逆性的提高有关，所以我们计划在哺乳动物和昆虫中研究这种调整，这些动物和昆虫暴露于死亡的嗅觉信号或其他动物应激或免疫激活的信号中。这些关于营养和风险对功能改变的反应的研究对生态种群和社区的功能有很大的影响。

A principle underlying how organisms evolve is that investments must be optimally balanced for successful living, but strong investments in one area require reductions in others. Functions (like growth and reproduction) do not simply compete for resources but allocation among them is a hormonally regulated "strategy" that adjusts to the environment. We are studying global regulation of functions using giant transgenic mice because greatly exaggerated growth allows us to see the relationship of other functions to growth and to each other. Of particular interest is the remarkable accelerated aging of these mice. Growth may divert resources from functions that forestall aging (e.g., pathways mediating stress resistance). We are learning more by developing dietary supplements that actually slow the aging rate of mice and insects. These allow us to see how slower aging is achieved. We recently found that insects and crustaceans recognize and avoid injured or dead relatives using particular odours. Such risk avoidance may be applied to control diverse pests. Moreover, crickets exposed to the odour of death not only altered their eyes, wings, and spines, they also lived longer. Food restriction is the only other known way of greatly extending longevity of most animals. However, benefits (including stress resistance) disappear if restricted animals can smell food. Thus, adjustments to risk of death or famine that increase life span both involve smell. Life extension is generally associated with elevated stress resistance so we plan to examine such adjustments in mammals and insects exposed to olfactory signals of death or signals indicating stress or immune activation in others. These studies of functional alterations in response to nutrition and risk have vast implications for how ecological populations and communities function.