SGER: Using Maize as a Model System to Study a Novel Family of Helitron Related Transposable Elements

转座元件在进化中起着不可或缺的作用，它们构成了真核生物基因组中最丰富的实体。Helitrons是最近发现的一类转座元件，显然是通过复制和链替换来转座的。尽管它们数量丰富，但没有直接的遗传证据或证据表明存在自主的氦电子。研究人员最近描述了两个由氦插入引起的玉米突变，并提供了第一个证据，表明活跃的氦可能存在于今天的玉米基因组中。这项用于探索性研究的小额赠款将建立活跃的氦电子的直接遗传学证据。这是一个高风险项目，因为认为这些玉米突变体是由相对较新的氦电子插入引起的断言是基于这些突变是在20世纪90年代分离出来的假设。然而，这些突变可能代表了早期没有发现的古代等位基因的残留物，这一可能性仍然很小。这种方法具有潜在的高回报，因为了解这一新型转座元件家族的转座模式可能会产生作物改良的工具，并为基因组结构和组织提供新的见解。该项目的目标是通过监测各种玉米品系的体细胞和可遗传逆转事件来从遗传上鉴定自治的氦电子。这对于明确确定一个自主的元素并建立玉米作为研究氦电子转座的系统是必不可少的。更广泛的影响：拟议的研究将为遗传学、分子生物学和生物信息学的本科生和研究生提供跨学科培训机会，并接触到参与实地实验的高中生。奥克兰大学专门开发了一门新课程，将生物信息学纳入本科生和研究生的主流课程。学生们将在基因发现和对拟议研究产生的序列数据进行注释方面获得实践经验。

Transposable elements have played an integral role in evolution and they constitute the most abundant entities in the eukaryotic genome. Helitrons are a recently-discovered family of transposable elements that apparently transpose through replication and strand replacement. Despite their abundance, there is no direct genetic evidence or proof for the existence of an autonomous Helitron. The investigators recently described two maize mutants that were caused by Helitron insertion and provided the first evidence that an active Helitron may reside in the present-day maize genome. This Small Grant for Exploratory Research will establish the direct genetic evidence of an active Helitron. This is high-risk project because the assertion that these maize mutants are caused by relatively recent insertion of Helitrons is based on the assumption that these were isolated in the 1900s. However, there remains a remote possibility that these mutants may represent remnants of ancient alleles that were not discovered earlier. The approach is potentially high pay-off because understanding the mode of transposition of this novel family of transposable elements may yield tools for crop improvement and provide novel insights into genome structure and organization. The objective of the project is to genetically identify the autonomous Helitron by monitoring various maize lines for somatic and heritable reversion events. This is essential in order to definitely identify an autonomous element and establish maize as a system to study the transposition of Helitrons. Broader Impact: The proposed research will provide interdisciplinary training opportunities for both undergraduate and graduate students in Genetics, Molecular Biology and Bioinformatics and reach out to high school students involved in the field experiments. A new course has been developed specifically to integrate Bioinformatics into the mainstream undergraduate and graduate curricula at Oakland University. The students will gain hands-on experience in gene discovery and annotation of sequence data generated by the proposed research.