DNA甲基化在寡孢节丛孢捕器形成过程中的作用及功能研究

Plant-parasitic nematode infection is the second most serious disease in agriculture and biological control is a potential approach to reduce the lost. Arthrobotrys oligospora is a typical nematophagous fungus and can generate special organ, nematode-trap, to immobilize and penetrate nematodes. This process is initiated by complex gene expression regulation, which is still unclear. Cytosine methylation is the major epigenetics modification in eukaryote genome and an ancient and widespread way to regulate gene expression. Moreover, this modification has been suggested to be involved in the mycelia growth and nematode-trap formation in A. oligospora. In this study, we attempt to illustrate the role and function of DNA methylation in A. oligospora nematode-trap formation. We plan to utilize bisulfite sequencing (BS-Seq) to obtain its methylome with single-base resolution. By comparing the methylomes from the mycelia with and without trap, the differentially methyalted gene (DMG) can be identified. Through gene ontology (GO) analysis, the enriched gene family can be obtained. Meanwhile, we will utilize multiple functional genomics methods to scrutinize the effect of DNA methylation on gene expression both in vivo and in vitro. Furthermore, we will perform gene knockout to generate specific mutant, followed by culture and inducing, in order to substantiate the role of DMGs in nematode-trap formation. This project will provide more insight into the molecular mechanism of life style switch and nematode capture in A. oligospora, and DNA methylation pattern and function in fungi genome.

植物病原线虫是农林生产的第二大病害，生物防治是最具潜力的措施。寡孢节丛孢是食线虫真菌的典型代表，可通过产生特殊器官捕器侵染和杀灭线虫，但这一过程的基因表达调控机理仍不清楚。胞嘧啶甲基化是真核生物基因组上的主要表观遗传学修饰，是一种广泛而古老的基因表达调控机制，并参与了寡孢节丛孢菌丝生长和捕器形成。本项目围绕寡孢节丛孢捕器形成过程中DNA甲基化的作用和功能这一关键问题，使用基于重亚硫酸盐处理的基因组测序技术，绘制其单碱基分辨率甲基化组图谱。通过对具备和不具备捕器的菌丝甲基化图谱的比较，搜索存在差异甲基化的基因，并使用基因本体分析鉴别富集的基因簇。进而应用多种功能基因组学手段，研究DNA甲基化在体内和体外对基因表达的调控。此外通过基因敲除构建特定基因缺陷株等方法，探讨这些基因在捕器形成过程中的作用。本项目对研究寡孢节丛孢生活方式转换和侵染线虫的分子机制、真菌基因组甲基化模式和功能具有重要意义。