摘要
DNA甲基化是表观遗传学的一个分支学科,因其在调控基因表达和生物体许多生理生化过程具有重要的作用,近年来逐渐受到广泛关注。昆虫由于种类繁多,变态发育和表型复杂,研究DNA甲基化的功能具有重要的意义。昆虫DNA甲基化需要由DNA甲基化转移酶(Dnmts)参与完成,其数量和结构在不同物种中差异较大。大多数昆虫均具有维持DNA甲基化水平的Dnmt1,缺乏行使从头DNA甲基化功能的Dnmt3,Dnmt2(也称为TRDMT1)虽保守存在但其DNA结合的能力极其微弱。昆虫DNA甲基化的总体水平较低,并且呈现不同龄期和组织的时空分布特异性。在昆虫基因组中,以外显子区的DNA甲基化水平最为显著,具有增强基因表达的功能,表现出在序列保守和广泛表达的基因中水平高、在特异表达的基因中水平低的进化特征。目前用于研究昆虫DNA甲基化的方法主要有生物信息学预测和甲基化特异限制性内切酶、甲基化敏感扩增多态性、基因组DNA甲基化测序等实验研究方法。本文就昆虫DNA甲基化转移酶的特性、DNA甲基化的分布与进化及其研究方法进行综述,旨在深入了解昆虫DNA甲基化的研究现状及其重要作用,为促进该研究领域的发展提供新的思路和方法。
DNA methylation is a branch of epigenetics that has been getting broad recognition and receiving extensive attention in recent years because of its important function in modulating gene expression and its association with many physiological and biochemical processes in living organisms. Their high species abundance, metamorphic development and complex phenotypes make the insects a useful group in which to explore the function of DNA methylation. DNA methylation in insects is mainly mediated by DNA methyltransferases（Dnmts）, which vary greatly in different species. Most insects possess Dnmt1 but lack Dnmt3, which are responsible for maintenance and de novo DNA methylation, respectively. Dnmt2（also termed TRDMT1） is ubiquitous among insects but its ability to bind DNA is weak. An overall low level, as well as spatio-temporal patterns of DNA methylation, are observed in insects. In insect genomes, DNA methylation is predominantly located in gene exons to functionally enhance gene expression, with higher methylation levels in evolutionarily conserved and extensively expressed genes, and lower levels in specifically expressed genes. The major methodologies currently used in the study of insect DNA methylation are summarized as bioinformatics-based prediction and experimentally-based techniques that include methylation specific restriction enzyme assays（MSRE）, methylation sensitive amplified polymorphism（MSAP） and genomic sequencing. This paper summarizes methyltransferases in insects, the distribution and evolution of DNA methylation, as well as available methodologies used in current studies. It provides a synthesis of important updates and potential applications, and novel ideas and technologies for further research in this area.
出处
《应用昆虫学报》
CAS
CSCD
北大核心
2015年第5期1082-1093,共12页
Chinese Journal of Applied Entomology
基金
国家自然科学基金国际合作重大项目(31320103922)
国家自然科学基金重点项目(31230061)
国家自然科学基金青年项目(31301677)
