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

进化是一个优化生物体内基因功能的过程，以促进在面对竞争和环境变化时的生存。虽然进化经常作为发明的引擎，但它在精简方面也起着重要作用，确保生物体不会浪费资源来维持或操作多余的功能。许多动物和植物已经进化出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。参与这些关联的微生物经历了从自主生活方式到植物或动物宿主提供许多需求的戏剧性转变。共生为进化流线型提供了自然界最有力的机会之一，通常导致超过90%的祖先微生物基因功能的丧失。本研究的重点是了解以羽毛为食的鸟虱细菌共生体的进化流线型过程。这些共生关系已经从几乎相同的伴侣（分别）进化了许多次，这些伴侣定居在不同的鸟类中，但具有相同的共生功能。对于进化过程的研究来说，这是一个罕见而又珍贵的场景，因为高水平的重复为随机变化和偶然性的作用提供了独特的见解。这项研究还将为中美学生和研究人员之间的科学整合提供一个框架，以及一个暑期“模拟生物”夏令营，该夏令营将训练7-9年级的学生开发能够破译进化过程模式和模式的计算机模拟。这个项目的重点是了解亲密和相互依存的共生关系是如何产生、发挥作用和共同进化的。虽然许多昆虫（以及其他动物和植物）已经与细菌进化出了共生关系，从而促进了重要新特征的获得，但本项目关注的是以羽毛为食的鸟虱，它们反复独立地与细菌进化出了共生关系，以获取羽毛角蛋白中缺乏的必需b族维生素。这些虱子异乎寻常的统一和简化的生活方式为研究在相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。本项目探讨(i)漂移和偶然性在共生细菌基因组进化和退化过程中的作用，以及（ii）综合功能的本质和机制基础。该项目采用以机器学习/人工智能算法为基础的新型比较基因组方法，检测高度复制的基因组数据集中的重复模式，这些数据集有效地代表了虱子共生进化的重播。这将对分子进化过程和共生特征的适应产生非常详细的见解，而且，进化促进自然界基因组流线型的机制。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.