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单个表皮细胞。每个棉铃大约产生50万根纤维，有些形成“绒毛”，有些形成可纺纤维。将表皮细胞转变为纤维细胞的过程需要改变细胞的命运，这是一个涉及遗传、生理和发育的基本生物过程。基因突变、基因分型、授粉/受精和激素调节都会影响发育成纤维的细胞数量或改变纤维细胞的性质。然而，目前还不清楚这些因素是如何控制基因表达变化的，这些基因表达变化协调了纤维发育早期的模式和节奏。遗传学和功能基因组学方法将被用来研究伴随纤维细胞启动的分子事件。将同基因裸种突变体的未成熟胚珠中基因表达的变化与已授粉和未授粉的胚珠以及经植物激素处理的胚珠中的表达谱进行比较。在导致纤维细胞起始的各种遗传、发育和生理条件下，将确定特定的和共同的候选基因集。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。更广泛的影响这个跨学科项目将对研究、教育和科学界产生广泛和直接的影响，创建供公众使用的基因组资源，并使其结果直接适用于世界领先的纺织纤维作物的改良和可持续性。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，一旦得到确认并协同应用，将立即向公共领域发布，以培养本科生、研究生和博士后，特别强调代表不足的群体。数据传播将包括将EST及时发布到GenBank，并将基因表达谱发布到GEO等微阵列数据库。将制定一项涉及研究生和博士后的综合计划，让中学的学生和科学教师及早接触生物技术和基因组学。将开发一个为期3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来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.