Dimensions: Collaborative Research: Integrating phylogenetic, genetic, and functional approaches to dissect the role of toxin tolerance in shaping Drosophila biodiversity

对环境的不寻常适应长期以来一直吸引着科学家和公众。已经有很多研究来理解形态结构的进化（例如，形状、颜色、大小）。然而，人们对新的生物化学适应的进化以及这些适应对它们出现的生物多样性的影响知之甚少。特别令人感兴趣的是，如果这些特征对拥有它们的人来说代价高昂，那么这些特征是如何产生的。这项研究调查了生物化学适应的进化以及塑造它们的遗传和生态机制。这项研究探索了昆虫（果蝇）对它们食用的蘑菇中的强效毒素的耐受性。通过研究毒素耐受性的机制以及这种独特的适应性如何在这个模型系统中保持，这项研究将增强对新特征如何出现和塑造生物多样性的普遍理解。该项目还包括旨在提高公众科学素养和熟悉生物多样性的活动，培训从中学到大学的教师和学生（特别是来自代表性不足的少数民族），并为与蘑菇有关的昆虫物种制作照片识别指南。果蝇的一些种群以有毒和无毒蘑菇为食，并且可以耐受高剂量的对大多数其他多细胞生物致命的强效环肽蘑菇毒素。这项研究测试的假设预测：1）对这些有毒环肽的耐受性进化了多次; 2）耐受性的遗传机制在所有物种中并不相同; 3）耐受性的生理成本和获得低竞争资源的好处之间的权衡维持耐受性。耐受性的机制和它们在不同的苍蝇物种的演变正在使用代谢组学和转录组学分析，在系统发育框架进行分析。为了评估毒素耐受性变异的遗传基础，研究人员正在进行人工选择实验和基因组测序。最后，观察和竞争实验正在被用来确定如何选择压力保持在自然种群的毒素耐受性。总之，这项研究将提供一个深入的进化，生态和生理评估的昂贵和新颖的生化适应，及其对生物多样性的影响。

Unusual adaptations to the environment have long fascinated scientists and the public. There has been much research to understand the evolution of morphological structures (e.g., shape, color, size). However, far less is known about the evolution of novel biochemical adaptations and the impact of these adaptations on the biodiversity of the organisms in which they appear. Of particular interest is how these traits arise if they are costly to the individuals who harbor them. This research investigates the evolution of biochemical adaptations and the genetic and ecological mechanisms that shape them. The research explores the tolerance of insects (fruit flies) to potent toxins in mushrooms that they consume. By investigating the mechanism of toxin tolerance and how this unique adaptation is maintained in this model system, the research will enhance the general understanding of how novel traits emerge and shape biodiversity. This project also includes activities designed to increase public scientific literacy and familiarity with biodiversity by training teachers and students, from middle school to the undergraduate level (particularly from underrepresented minorities), and generating photographic identification guides for insect species associated with mushrooms.Flies from some groups of Drosophila feed on both toxic and non-toxic mushrooms, and can tolerate high doses of potent cyclopeptide mushroom toxins that are deadly to most other multi-cellular organisms. This research tests hypotheses that predict that: 1) tolerance to these toxic cyclopeptides evolved multiple times; 2) the genetic mechanism of tolerance is not the same in all species; and 3) trade-offs between the physiological costs of tolerance and the benefits of access to a low-competition resource maintain tolerance. The mechanisms of tolerance and their evolution within different fly species are being characterized using metabolomic and transcriptomic analyses that are analyzed in a phylogenetic framework. To assess the genetic basis of variation in toxin tolerance, the researchers are performing artificial selection experiments and genome sequencing. Finally, observational and competition experiments are being used to identify how selective pressures maintain toxin tolerance in natural populations. In sum, this research will provide an in-depth evolutionary, ecological, and physiological assessment of a costly and novel biochemical adaptation, and its impact on biodiversity.