HAP2 (GCS1): Mechanisms of Double Fertilization

Mark A.约翰逊 IOS-1021917 HAP 2（GCS 1）：双受精机制允许配子细胞（精子和卵子）融合的分子机制尚不清楚。克服我们知识中的这一差距是一个重要的目标，因为配子融合是所有有性生殖生物生命周期的核心。开花植物（包括玉米、水稻和大豆等主要作物）经历双受精：一个精子与卵细胞融合形成胚胎，另一个精子与中央细胞融合产生胚乳，胚乳是支持胚胎的专门组织。这些细胞融合事件导致种子的形成，这是人类食物系统的基础。对开花植物中配子融合的更深入了解将导致可以提高种子作物产量和控制作物繁殖的技术。在模式植物拟南芥中使用遗传分析鉴定hap 2 -1突变体。hap 2 -1突变的精子看起来正常，但不能与卵子或中央细胞融合。 这些突变体缺乏一种蛋白质HAP 2（GCS 1），这种蛋白质通常位于精子细胞的表面。在这个项目中将要测试的假设是，HAP 2（GCS 1）蛋白直接参与了一个允许雄性和雌性配子融合的过程。 该项目的目标是1）鉴定参与HAP 2（GCS 1）介导配子融合的新蛋白质，2）鉴定调节HAP 2（GCS 1）功能的蛋白质，3）确定HAP 2（GCS 1）和其他蛋白质如何允许配子细胞融合。 该项目的结果将产生广泛的科学影响，因为HAP 2（GCS 1）存在于许多真核生物物种中，并且可能是许多植物和动物采用的配子融合机制的一部分。 该项目将为不同背景的男女本科生、研究生和博士后研究人员提供尖端研究培训。该项目还包括一个面向当地中小学学生和教师的外联部分。

Mark A. Johnson IOS-1021917HAP2(GCS1): Mechanisms of double fertilizationThe molecular mechanisms that allow gamete cells (sperm and egg) to fuse are unknown. Overcoming this gap in our knowledge is an important goal because gamete fusion is central to the life cycle of all sexually reproducing organisms. Flowering plants (including major crops like corn, rice, and soybean) undergo double fertilization: one sperm fuses with the egg cell to form an embryo and another sperm fuses with the central cell to produce endosperm, a specialized tissue that supports the embryo. These cell fusion events lead to formation of seeds, the basis of the human food system. Gaining greater understanding of gamete fusion in flowering plants will lead to technologies that can improve seed crop production and control reproduction of crop plants. The hap2-1 mutant was identified using genetic analysis in the model plant species Arabidopsis thaliana. hap2-1 mutant sperm appear normal, but fail to fuse with either the egg or the central cell. These mutants lack a protein, HAP2(GCS1), that is normally on the surface of sperm cells. The hypothesis that will be tested in this project is that the HAP2(GCS1) protein is directly involved in a process that allows the male and female gametes to fuse. The goals of this project are 1) to identify new proteins that participate with HAP2(GCS1) to mediate gamete fusion, 2) to identify proteins that regulate the function of HAP2(GCS1), and 3) to determine how HAP2(GCS1) and other proteins allow gamete cells to fuse. The results of this project will have broad scientific impacts because HAP2(GCS1) is found in many eukaryotic species and is likely part of a gamete fusion mechanism employed by many plants and animals. This project will provide cutting-edge research training for both female and male undergraduate, graduate, and post-doctoral researchers of diverse backgrounds. This project also includes an outreach component to local elementary and high school students and teachers.