Dimensions US-China: Collaborative Research: Functional Genomics and Experimental Endosymbiont Replacements in Lice.

进化是在面对竞争和环境变化的情况下，优化有机体内基因的功能以促进生存的过程。虽然进化经常作为发明的引擎，但它也在精简程序方面发挥着重要作用，确保生物体不会浪费资源维持或运行多余的功能。许多动植物进化出了与微生物的共生关系，以便获得它们自己的基因组清单所不提供的功能。参与这些协会的微生物经历了一种戏剧性的转变，从一种自主的生活方式转变为一种由植物或动物宿主提供许多需求的生活方式。共生提供了自然界最有效的进化精简机会之一，通常会导致90%以上的祖先微生物基因功能丧失。本研究旨在了解食羽鸟虱子细菌共生体的进化流线型过程。这些共生体多次(分别)从近乎相同的伙伴进化而来，这些伙伴殖民了不同的鸟类，但具有相同的共生功能。对于进化过程的研究来说，这是一个罕见且非常有价值的场景，因为高水平的重复提供了对随机变化和偶然性作用的独特洞察。这项研究还将为中美学生和研究人员之间的科学融合提供一个框架，以及一个将培训7-9年级学生开发能够破译进化过程模式和模式的计算机模拟的暑期“SIM-Biosis”夏令营。这个项目的重点是了解亲密和相互依赖的共生关系是如何起源、发挥作用和共同进化的。虽然许多昆虫(以及其他动植物)已经进化出与细菌的共生关系，从而促进了重要新特征的获得，但该项目重点关注以羽毛为食的鸟类虱子，它们反复独立地与细菌进化共生关系，以获得它们的羽毛角蛋白饮食中所缺乏的必要的B族维生素。这些虱子不同寻常的统一和简化的生活方式为研究在类似条件下反复获得共生体的进化结果提供了一个独特的机会。该项目探索(I)漂移和偶然性在塑造共生细菌基因组进化和退化过程中的作用，以及(Ii)整合功能的性质和机制基础。该项目使用机器学习/人工智能算法支持的新的比较基因组方法来检测高度复制的基因组数据集中的重复模式，这些重复模式有效地代表了虱子共生进化的回放。这将对以共生为特征的分子进化过程和适应，以及进化促进自然界基因组精简的机制产生非常详细的洞察。这一奖项反映了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。

Evolution is a process that optimizes the functions of genes within an organism to facilitate survival in the face of competition and environmental change. While evolution often serves as an engine of invention, it also plays an important role in streamlining, ensuring that organisms do not waste resources maintaining or operating superfluous functions. Many animals and plants have evolved symbiotic relationships with microbes in order to gain access to functions that their own genomic inventories do not provide. Microbes participating in these associations experience a dramatic shift from an autonomous lifestyle to one in which their plant or animal host provides many of their needs. Symbiosis provides one of nature's most potent opportunities for evolutionary streamlining, often resulting in the loss of over 90% of ancestral microbial gene functions. This research focuses on understanding the process of evolutionary streamlining in bacterial symbionts of feather-feeding bird lice. These symbioses have evolved (separately) many times from near-identical partners that have colonized different birds but have the same symbiotic functionality. This is a rare and highly prized scenario for the study of an evolutionary process because the high level of repetition provides unique insight into the roles of random change and contingency. This research will also provide a framework for science integration between Chinese and US students and researchers, along with a summer "SIM-biosis" camp that will train 7-9th grade students to develop computer simulations that can decipher the modes and patterns of evolutionary processes. This project focuses on understanding how intimate and interdependent symbiotic relationships originate, function, and co-evolve. While many insects (along with other animals and plants) have evolved symbiotic relationships with bacteria that facilitate the acquisition of important new traits, this project focuses on feather-feeding bird lice, which have repeatedly and independently evolved symbiotic relationships with bacteria to obtain essential B-vitamins that are lacking in their diet of feather keratin. The unusually uniform and simplified lifestyle of these lice presents a unique opportunity to study the evolutionary outcome of repeated acquisition of symbionts under similar conditions. This project explores (i) the role of drift and contingency in shaping the processes of genome evolution and degeneration in symbiotic bacteria, and (ii) the nature and mechanistic basis of integrated functionality. The project uses novel comparative genomic approaches underpinned by machine learning/artificial intelligence algorithms to detect repeating patterns in highly-replicated genomic datasets that effectively represent replays of symbiosis evolution in lice. This will yield highly detailed insight into the molecular evolutionary processes and adaptations that characterize symbiosis and, moreover, the mechanism by which evolution facilitates genomic streamlining in nature.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.