NSF Postdoctoral Fellowship in Biology FY 2016

这一行动为NSF国家植物基因组计划2016财年生物学博士后研究奖学金提供了资金。该奖学金支持在东道主实验室为该研究员制定的研究和培训计划，该研究员还提出了扩大生物学参与度的计划。Bradlee Nelms的这项研究和培训计划的标题是“玉米孢原细胞在花药发育早期的指定和分化”。该奖学金的主办机构是斯坦福大学，赞助科学家是弗吉尼亚·沃尔伯特博士。奖学金活动的重点是了解玉米花药的早期发育。玉米花药作为一种主要农作物的生殖器官，在许多重要的农艺过程中起着核心作用。在许多粮食作物中，花药发育早期的缺陷会导致雄性不育，导致籽粒数和产量下降。此外，高温和干旱造成产量损失的最早原因之一是花粉不存活；因此，了解花药发育和雄性可育性对于确保气候变化下的粮食安全将是重要的。该项目将增加基本生殖生物学的知识，这些信息最终可能导致作物育种和产量提高方面的突破。研究金活动还将在学术界和公众中促进教与学。该研究员将领导一个以本科生为重点的外展项目，设计和销售教育材料，帮助向社会传播植物科学的广泛重要性，并鼓励来自科学领域和其他学科的本科生之间的合作。进一步的教育推广将包括在实验室研究中指导本科生和高中生。这项研究的首要科学目标是揭示原生孢子(AR)细胞发育的早期事件--花药内致力于减数分裂和花粉产生的第一种细胞类型。主要目的是(1)确定AR细胞分化为小细胞的细胞中间体；(2)研究TGA类转录因子在AR细胞特性中的作用。这些目标将利用基因组学、遗传学和生物化学的组合来实现。单细胞RNA测序将允许识别不同的AR细胞群体，然后通过整合转录组数据和RNA转录本的原位定位来将这些细胞群体排序到一条发育途径中。几种TGA转录因子的亚细胞定位、氧化还原状态和DNA结合活性将在花药早期在各种遗传和生理扰动下进行评估，而TGA因子的下游信号通路将通过染色质免疫沉淀进行评估。总之，这些联谊会活动将产生大量的转录和芯片序列数据，阐明AR细胞发育的分化程序，并有助于在时空背景下表征AR细胞规范过程中TGA家族转录因子的调控和信号转导。研究成果将在国家会议上公布，并在同行评议的期刊上发表，所有序列数据将提交给公共存储库，如美国国家生物信息学研究所序列读取档案(http://www.ncbi.nlm.nih.gov/sra)和基因表达总览(http://www.ncbi.nlm.nih.gov/geo/).)

This action funds an NSF National Plant Genome Initiative Postdoctoral Research Fellowship in Biology for FY 2016. 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 Bradlee Nelms is "Specification and Differentiation of Maize Archesporial Cells During Early Anther Development." The host institution for the fellowship is Stanford University and the sponsoring scientist is Dr. Virginia Walbot.The fellowship activities are focused on understanding early anther development in maize. As a reproductive organ of a major crop plant, the maize anther plays a central role in many processes of agronomic importance. Defects in early anther development lead to male sterility, decreasing grain number and yield in many cereal crops. Furthermore, one of the earliest causes of yield loss in response to heat and drought is pollen inviability; thus, understanding anther development and male fertility will be important to insuring food security in the face of climate change. This project will increase knowledge of basic reproductive biology, information that can ultimately lead to breakthroughs in crop breeding and yield enhancement. The fellowship activities will also promote teaching and learning both within academia and in the general public. The fellow will lead an undergraduate-focused outreach project to design and market educational materials, helping to communicate the broad importance of the plant sciences to the community and stimulating collaboration between undergraduates from scientific fields and other disciplines. Further educational outreach will include mentoring undergraduate and high school students in laboratory research.The overarching scientific goal of this research is to uncover early events in the development of archesporial (AR) cells--the first cell type within the anther committed to meiosis and pollen production. Major aims are to (1) identify cellular intermediates as AR cells differentiate into meiocytes and (2) investigate the role of TGA-type transcription factors in AR cell specification. These aims will be pursued using a combination of genomics, genetics, and biochemistry. Single-cell RNA sequencing will allow the identification of distinct AR cell populations, which will then be ordered into a developmental pathway by integrating transcriptome data with in situ localization of RNA transcripts. The subcellular localization, redox status, and DNA binding activity of several TGA transcription factors will be assessed in early stage anthers under various genetic and physiological perturbations, and downstream signaling pathways for the TGA factors will be evaluated by chromatin immunoprecipitation. Together, the fellowship activities will generate substantial transcriptomic and ChIP-Seq data, clarify the differentiation program of AR cell development, and help to characterize the regulation and signaling of TGA family transcription factors during AR cell specification in a spatio-temporal context. Research results will be presented at national conferences and published in peer-reviewed journals, and all sequence data will be submitted to public repositories such as the NCBI Sequence Read Archive (http://www.ncbi.nlm.nih.gov/sra) and Gene Expression Omnibus (http://www.ncbi.nlm.nih.gov/geo/).