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

转座因子在进化过程中发挥了不可或缺的作用，它们构成了真核生物基因组中最丰富的实体。Helitrons是最近发现的转座因子家族，显然通过复制和链替换进行转座。尽管它们很丰富，但没有直接的遗传证据或证据证明自主Helitron的存在。研究人员最近描述了两种由Helitron插入引起的玉米突变，并提供了第一个证据，证明活跃的Helitron可能存在于当今的玉米基因组中。这笔用于探索性研究的小额赠款将建立一个活跃的Helitron的直接遗传证据。这是一个高风险的项目，因为断言这些玉米突变体是由相对较新的helitron插入引起的，是基于这些突变体在20世纪被分离出来的假设。然而，仍然存在一种可能性，即这些突变体可能代表了早期未被发现的古代等位基因的残余。该方法具有潜在的高回报，因为了解这种新型转座因子家族的转座模式可能为作物改良提供工具，并为基因组结构和组织提供新的见解。该项目的目的是通过监测各种玉米品系的体细胞和遗传逆转事件，从遗传上鉴定自主Helitron。这对于明确地识别一个自主元素和建立玉米作为一个系统来研究helitron的转位是必不可少的。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的培训机会，并延伸到参与实地实验的高中生。奥克兰大学专门开设了一门新课程，将生物信息学纳入主流本科和研究生课程。学生将获得基因发现的实践经验，并对拟议研究产生的序列数据进行注释。

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.