NSF Postdoctoral Fellowship in Biology: Ordered Evolution and Muscle-Specific Specializations of Constriction Behaviors in Snakes

这一行动为NSF 2022财年生物学博士后研究奖学金提供了资金，综合研究调查了基因组、环境和表型之间相互作用的生命规则。该奖学金支持研究员的研究和培训，这些研究员将以创新的方式为生活规则领域做出贡献。长期以来，蛇的收缩一直被认为是帮助蛇变得极其多样化和广泛分布的一个重要特征。这种行为相当复杂，很可能是从简单的蛇与猎物搏斗而不是盘绕进化而来的。这位研究员将研究这种有序进化是如何发生的，创建一个新的框架来理解复杂的特征是如何在自然界中进化的。这种多方面的方法将包括在蛇的族谱上绘制不同的“收缩”形式，研究它们肌肉的专门化，以及调查这些特征是如何受到基因调控的。此外，作为一名第一代低收入学生，这位研究员将通过让来自高中的学生参与行为观察和蛇的亲身实验来展示他所经历的机会。在高中，90%的学生来自代表不足的群体。当祖先的特征变得复杂时，新的特征往往会出现。然而，反复“建立”这些复杂特征的机制，即表型多样性的基本方面，仍然不清楚。蛇的“收缩”例证了生理和分子系统是如何相互交织以维持生命的。“收缩”描述的是层次化的复杂模式，包括(1)完全环状线圈收缩；(2)部分环状发夹环状；以及(3)类似摔跤的简单小齿轮。这些并不是相互排斥的，尽管肌肉质量或横截面积没有增加(力量的两个相关因素)，但更复杂的形式提高了表现。这表明“肌肉收缩”是通过一个有序的过程进化而来的，它涉及肌肉的专门化以产生复杂性。这个项目将使用系统发育比较的方法对蛇的收缩行为进行分类，以确定是否发生了有序进化。这位研究员将进行肌肉实验，以确定复杂的蟒蛇是否有专门用于产生力量或抵抗疲劳的肌肉。这项工作还将确定与先前实验中测量到的变异相关的每种“收缩”形式之间的遗传差异。这位研究员将在系统发育比较方法、行为生理学和转录组学方面获得经验，以加强他未来的研究计划，并探索是什么让蛇如此成功。作为该项目的一部分，该研究员将从当地一所高中的代表性不足的群体中招募感兴趣的学生来协助进行实验，以增强他们将自己视为未来STEM研究人员的能力。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2022, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment and Phenotypes. The fellowship supports research and training of the Fellow that will contribute to the area of Rules of Life in innovative ways. Constriction in snakes has been long thought to have been an important trait that helped snakes become extremely diverse and widespread. This behavior is quite complex and likely evolved from simpler versions where the snake wrestles its prey instead of coiling. The Fellow will study how this ordered evolution occurred, creating a new framework to understand how complex traits evolve in nature. This multifaceted approach will involve mapping different ‘constriction’ forms on the snake family tree, studying specializations of their muscles, and investigating how these traits are genetically regulated. Moreover, as a first-generation, low-income student, the Fellow will pay forward opportunities he experienced by involving students from a high school, where 90% of the students are from underrepresented groups, in behavioral observations and hands-on experiments with snakes.Novel traits often emerge when ancestral traits gain complexity. However, the mechanisms that iteratively “build” these elaborate traits, fundamental aspects of phenotypic diversity, remain unclear. ‘Constriction’ in snakes exemplifies how physiological and molecular systems intertwine to sustain life. ‘Constriction’ describes hierarchically complex patterns that include (1) fully looping coil constriction; (2) partially encircling hairpin looping; and (3) simple pinioning, similar to wrestling. These are not mutually exclusive, and more complex forms have increased performance despite lacking increases in muscle mass or cross-sectional area (two correlates of force). This suggests ‘constriction’ evolved through an ordered process and involved muscle specialization to produce complexity. This project will categorize constriction behaviors within snakes using phylogenetic comparative methods in order to determine whether ordered evolution occurred. The Fellow will conduct muscle experiments to determine whether complex constrictors have muscles specialized for force production or fatigue resistance. This work will also identify genetic differences between each ‘constriction’ form associated with the variation measured in the former experiments. The Fellow will gain experience with phylogenetic comparative methods, behavioral physiology, and transcriptomics to enhance his future research program and probe what makes snakes so successful. As part of this project, the Fellow will recruit interested students from underrepresented groups at a local high school to assist with experiments that enhance their ability to see themselves as future STEM researchers.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.