Male Gametes of Maize: Molecular Identification, Tracking, and Sorting

玉米雄配子：分子识别、跟踪和分选

• 批准号: 9630111
• 负责人: H. Lloyd Mogensen
• 金额: $ 21万
• 依托单位: Northern Arizona University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-07-01 至 2000-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9630111&HistoricalAwards=false
• 关键词: Male; Gametes; Maize; Molecular; Identification

9630111 Mogensen The pollen grain of flowering plants produces two sperm cells, each of which is utilized in a fertilization event. One sperm fuses with the egg to produce the embryo, and the other sperm fuses with the polar nuclei to produce the stored food within the seed. In corn, the two sperm cells are not recognizably different from each other based on morphology, however, a molecular probe has recently been developed that allows the identification of one sperm cell from the other within pollen and pollen tubes. The probe is based on the recognition of a Beta chromosome-specific DNA sequence. In corn lines containing two Beta chromosomes, only one of the sperm cells receives the Beta chromosomes, and this sperm cell preferentially fertilizes the egg. The use of this probe will form the basis of the research project. Using fluorescence in situ hybridizaiton analysis, we propose to: 1) Directly study B chromosome behavior during pollen development. 2) Track a given sperm type during pollen tube growth. 3) Separate the two sperm types from each other using flow cytometry and cell sorting. 4) Compare the two sperm types with regard to their fertilization abilities in vitro. This research promises to provide long sought after knowledge about basic aspects of Beta chromosome and sperm cell behavior, and will set the stage for further studies on sperm-specific characterizations at the biochemical and molecular levels. Such information will be of direct importance to sexual reproduction in maize specifically, and flowering plants in general.

9630111 Mogensen开花植物的花粉粒产生两个精细胞，每个精细胞用于受精事件。 一个精子与卵子融合产生胚胎，另一个精子与极核融合产生种子内储存的食物。 在玉米中，两个精细胞在形态学上彼此没有明显的不同，然而，最近开发了一种分子探针，可以在花粉和花粉管中识别一个精细胞。 该探针基于对β染色体特异性DNA序列的识别。 在含有两条β染色体的玉米品系中，只有一个精子细胞接受β染色体，并且该精子细胞优先使卵子受精。 该探头的使用将构成研究项目的基础。 利用荧光原位杂交技术，我们提出：1）直接研究花粉发育过程中B染色体的行为。2)在花粉管生长过程中跟踪给定的精子类型。3)使用流式细胞术和细胞分选将两种精子类型彼此分离。4)比较两种精子在体外受精的能力。 这项研究有望提供长期以来寻求的关于β染色体和精子细胞行为的基本方面的知识，并将为在生化和分子水平上进一步研究精子特异性特征奠定基础。 这些信息对于玉米的有性繁殖和一般开花植物的有性繁殖具有直接的重要性。