Genetic and Functional Genomic Analysis of Early Events in Cotton Fiber Development

棉花占世界天然纤维消费量的近一半。每根棉纤维是胚珠的一个分化的表皮细胞。每个棉铃大约生产50万根纤维，有些形成“绒毛”，有些形成可纺纤维。表皮细胞转变为纤维细胞的过程需要细胞命运的改变，这是一个涉及遗传、生理和发育“开关”的基本生物学过程。基因突变、基因型、授粉/受精和激素调节可以影响发育成纤维的细胞数量或改变纤维细胞的特性。然而，目前尚不清楚这些因素是如何控制基因表达变化的，这些基因表达变化在纤维发育的早期阶段协调了模式和节奏。遗传学和功能基因组学方法将用于研究伴随纤维细胞起始的分子事件。等基因裸种子突变体未成熟胚珠中基因表达的变化将与授粉和未授粉胚珠以及植物激素处理胚珠的表达谱进行比较。特异性和共同的候选基因将在导致纤维细胞起始的各种遗传、发育和生理条件下被鉴定。此外，关于候选基因在纤维细胞起始中的作用的假设将使用等基因突变体和强大的拟南芥遗传学进行严格的测试。更广泛的影响这一跨学科项目将通过创造供公众使用的基因组资源，并将其结果直接应用于世界领先的纺织纤维作物的改进和可持续性，对研究、教育和科学界产生广泛而直接的影响。遗传和基因组资源，如裸种子突变体、20,000个表达序列标签（est）、分子标记和寡基因微阵列等，一旦得到确认，就会向公众发布，并协同应用于培养本科生、研究生和博士后，特别强调代表性不足的群体。数据传播将包括及时向GenBank发布est和向GEO等微阵列数据库发布基因表达谱。将制定一项包括研究生和博士后的综合计划，使中学生和科学教师尽早接触生物技术和基因组学。将举办一个为期三天的教育讲习班，以促进公众对植物生物技术的接受，并通过动手实验、实验室参观和实地考察培训学生和科学教师。

Cotton represents nearly half of the world's natural fiber consumption. Each cotton fiber is a differentiated single epidermal cell of the ovule. Approximately half a million fibers are produced per cotton boll, some forming "fuzz" and some forming spinnable fibers. The process of turning an epidermal cell into a fiber cell requires a change in cell fate, a fundamental biological process involving genetic, physiological, and developmental "switches". Genetic mutations, genotypes, pollination/fertilization, and hormonal regulation can affect the number of cells developing into fibers or alter fiber cell properties. However, it is unclear how these factors control gene expression changes that orchestrate the pattern and tempo in early stages of fiber development. Genetic and functional genomic approaches will be employed to investigate molecular events concomitant with fiber cell initiation. Changes in gene expression in immature ovules of isogenic naked seed mutants will be compared with expression profiles in pollinated and un-pollinated ovules and ovules treated with phytohormones. Both specific and common sets of candidate genes will be identified in a variety of genetic, developmental, and physiological conditions leading to fiber cell initiation. Furthermore, hypotheses concerning the roles of candidate genes in fiber cell initiation will be rigorously tested using the isogenic mutants and powerful Arabidopsis genetics. Broader ImpactsThis interdisciplinary project will have broad and direct impacts on research, education, and the scientific community by creating genomic resources for public use and rendering their results directly applicable to the improvement and sustainability of the world's leading textile fiber crop. Genetic and genomic resources such as naked seed mutants, 20,000 expressed sequence tags (ESTs), molecular markers and oligo-gene microarrays will be released to the public domain as soon as they are confirmed and applied synergistically to train undergraduate and graduate students and postdocs with a special emphasis on under-represented groups. Data dissemination will include timely release of ESTs to GenBank and gene expression profiles to microarray data repositories such as GEO. An integrated plan involving graduate students and postdocs will be developed for early exposure of students and science teachers in middle schools to biotechnology and genomics. A 3-day educational workshop will be developed to promote public acceptance of plant biotechnology, as well as to train students and science teachers using hands-on experiments, laboratory tours, and field trips.