NSF Postdoctoral Fellowship in Biology FY 2021: Leveraging Frequent Monoicy-dioicy Transitions in Hornworts to Understand the Rules of Sex Determination

2021 财年 NSF 生物学博士后奖学金：利用金鱼藻频繁的单性-双性转变来了解性别决定的规则

• 批准号: 2109789
• 负责人: Peter Schafran
• 金额: $ 21.6万
• 依托单位: Schafran, Peter W
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2109789&HistoricalAwards=false
• 关键词: NSF; Postdoctoral; Fellowship; Biology; FY

This action funds an NSF Plant Genome Postdoctoral Research Fellowship in Biology for FY 2021. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The title of the research and training plan for this fellowship to Peter Schafran is "Leveraging frequent monoicy-dioicy transitions in hornworts to understand the rules of sex determination" The host institution for the fellowship is the Boyce Thompson Institute and the sponsoring scientist is Dr. Fay-Wei Li.In animals sex determination is fairly consistent across diverse groups, such as the XY chromosomes that originated once in the common ancestor of all placental mammals including dogs, cows, humans, elephants, whales, etc., over 166 million years ago. In contrast, the evolution of separate sexes in plants has occurred many times and over much shorter time periods. One plant group that shows this is hornworts, in which about half of all species have separate sexes that evolved from hermaphroditic ancestors at least 14 separate times. To understand why sexual system evolution is so flexible in plants, this project will examine how genes and chromosome structure change each time a species evolves to have separate male/female individuals. New genomes will be generated from hermaphroditic and male/female hornwort species representing over 300 million years of evolution in order to determine common genes that may be prerequisites for formation of separate sexes. This project will also examine patterns of change in genome architecture over time, as sex-determining genes eventually cause the formation of sex chromosomes, which then may be more likely to degrade. Identifying these processes in hornworts will uncover mechanisms that may provide a model for evolution of separate sexes across all plants and a contrast for the starkly different pattern in animals. A better understanding of how chromosomes and genes function will enhance efforts to improve crop plants. This project will provide varied opportunities for training high school and undergraduate students in tissue culture, genome assembly, comparative genomics, and plant transformation. This project will leverage multiple monoicy-dioicy transitions across the hornworts in order to test whether common rules govern the evolution of sex-linked genes and sex chromosomes. Evidence will be drawn from a broad range of phylogenetic diversity, evolutionary time, genomic scales, and gene-phenotype associations. Three specific objectives are: 1) characterize the structure and composition of hornwort sex chromosomes; 2) identify candidate sex-determining genes by examining genes associated with sex chromosomes and under selection in multiple lineages; 3) functionally characterize candidate sex-determining genes by transgenically over-expressing them in the monoicous model hornwort Anthoceros agrestis. Multiple genome assembly techniques will be used to create 19 new hornwort genomes representing monoicous and dioicous species assembled to pseudochromosome level. Genetic analyses will examine gene orthologs from pairs of monoicous and dioicous species to identify those with evidence of selection across multiple independent transitions between monoicy and dioicy. For genes found to recurrently appear to be selected for on sex chromosomes, their over-expression in A. agrestis is expected to affect the successful development gametes/gametangia and their ability to form viable sporophytes. The expected results will contribute functional knowledge about specific genes, and about the associated chromosome structural and compositional variations that lead to formation of sex chromosomes. All data will be publicly available through GenBank as well as HornwortBase, a new platform for hornwort genomic analysis (www.hornwortbase.org). Results will be communicated through public lectures and open access publications.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.

该行动为2021财年的生物学生物学研究奖学金提供了一项NSF植物基因组基因组研究奖学金。该奖学金支持该研究员的主机实验室研究和培训计划，该研究员还提出了扩大生物学参与的计划。这项与彼得·沙夫兰（Peter Schafran）奖学金的研究和培训计划的标题“利用霍恩沃特（Hornworts）在霍恩沃特（Hornworts）中频繁的单次二行过渡来理解性别确定的规则”奖学金的主机机构是博伊斯·汤普森研究所（Boyce Thompson Institute），并且赞助的货币科学家是vay-wei li.in li.in li.in li.in sexion sextions，例如一致性，像xy族人相当一致。在所有胎盘哺乳动物中，包括狗，牛，人类，大象，鲸鱼等，超过1.66亿年前。相比之下，植物中单独的性别的演变发生了很多次，并且在较短的时间段内。一个表明这是霍恩沃特的植物群，其中大约一半的物种具有独立的性别，这些性别至少从雌雄同体祖先演变至少14次。为了了解为什么性系统进化在植物中如此灵活，该项目将检查每次物种都会演变成具有分开的男性/女性的基因和染色体结构如何变化。为了确定可能是形成单独性别的先决条件的常见基因，将从雌雄同体和男性/女性霍恩沃特物种产生新的基因组。该项目还将检查基因组结构随时间变化的模式，因为性别确定的基因最终会导致性染色体的形成，然后这可能更有可能降解。识别霍恩沃尔特（Hornworts）中的这些过程将发现可能为所有植物中单独性别演化的模型提供模型，并与动物中截然不同的模式形成鲜明对比。更好地了解染色体和基因功能如何增强改善作物植物的努力。该项目将为培训组织培养，基因组组装，比较基因组学和植物转化的高中和本科生提供各种机会。该项目将利用整个霍恩沃特的多个单次二行过渡，以测试共同的规则是否控制与性别相关的基因和性染色体的演变。证据将从多种系统发育多样性，进化时间，基因组量表和基因 - 表型关联中得出。三个特定目标是：1）表征霍恩沃特性染色体的结构和组成； 2）通过检查与性染色体相关的基因以及在多个谱系中选择的基因来确定候选性别确定的基因； 3）通过在单基因霍恩沃特Anthoceros Agrestis中跨基因过表达候选性别确定基因的功能表征。多种基因组组装技术将用于创建19个代表单核和二核物种的新的霍恩沃特基因组，这些基因组组装到伪色素体水平。遗传分析将从成对的单核和二核物种对基因直系同源物进行基因直系同源物，以识别那些在单季和二行之间进行多个独立过渡的选择证据的人。对于发现反复选择的基因似乎是在性别染色体上选择的，预计它们在A. Agrestis中的过表达将影响成功的发展配子/Gametangia及其形成可行的孢子菌素的能力。预期的结果将有助于有关特定基因的功能知识，以及导致形成性染色体的相关染色体结构和组成变化。所有数据将通过GenBank和HornwortBase公开获得，HornwortBase是Hornwort基因组分析的新平台（www.hornwortbase.org）。结果将通过公开讲座和开放访问出版物进行传播。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的审查标准来评估值得支持的。