NSF Postdoctoral Fellowship in Biology FY 2016

该行动资助了2016财年NSF国家植物基因组计划生物学博士后研究奖学金。该研究金支持研究员在东道实验室的研究和培训计划，研究员还提出了扩大生物学参与的计划。这项研究和培训计划的标题是“玉米花药发育早期孢原细胞的特化和分化”。“该研究金的主办机构是斯坦福大学，赞助科学家是Virginia Walbot博士，研究金活动的重点是了解玉米早期花药发育。玉米花药作为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。早期花药发育的缺陷导致雄性不育，在许多谷类作物中减少粒数和产量。此外，炎热和干旱导致产量损失的最早原因之一是花粉失活;因此，了解花药发育和雄性育性对于在气候变化面前确保粮食安全至关重要。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提高产量的突破。研究金活动还将促进学术界和公众的教学。该研究员将领导一个以本科生为重点的外联项目，设计和销售教育材料，帮助向社区宣传植物科学的广泛重要性，并促进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指导本科生和高中生进行实验室研究。这项研究的首要科学目标是揭示孢原（AR）细胞发育的早期事件-花药中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）鉴定AR细胞分化为性母细胞时的细胞中间体，（2）研究TGA型转录因子在AR细胞特化中的作用。这些目标将通过基因组学、遗传学和生物化学的结合来实现。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与RNA转录本的原位定位将其排序为发育途径。亚细胞定位，氧化还原状态，和DNA结合活性的几个TGA转录因子将在早期花药在各种遗传和生理扰动下进行评估，和下游信号转导途径的TGA因子将通过染色质免疫沉淀法进行评估。这些奖学金活动将产生大量的转录组学和ChIP-Seq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细胞特化过程中TGA家族转录因子的调控和信号传导。研究结果将在全国性会议上发表，并发表在同行评议的期刊上，所有序列数据将提交给公共资料库，如NCBI Sequence Read Archive（http：//www.ncbi.nlm.nih.gov/sra）和Gene Expression Omnibus（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/).