植物基因组编辑新工具——引导编辑技术

基于CRISPR/Cas9系统的引导编辑(prime editing,PE)技术作为一种新兴的基因组编辑技术,能在不产生双链断裂的情况下实现所有12种单碱基替换和小片段DNA的缺失或插入.引导编辑技术已经在多种植物中成功应用并将在植物精准育种中发挥重要作用.虽然植物引导编辑(plant prime editing,PP...     

新一代基因组编辑系统CRISPR/Cpf1

CRISPR/Cas系统几乎存在于所有的细菌和古菌中,是用来抵御外来病毒和噬菌体入侵的获得性免疫防御机制。2012年起CRISPR/Cas9被改造为基因编辑工具,并衍生出一系列高效、便捷的基因编辑工具,迅速在基础理论、基因诊断和临床治疗等研究领域中得到广泛应用。然而,CRISPR/Cas9也存在细胞毒性、脱靶效应和基因插入困难等一些亟待解决的问题,在一定程度上限制了CRISPR/Cas9的应用。Cpf1是2015年报道的一种新型CRISPR效应蛋白,具有许多与Cas9不同的特性,有利于克服CRISPR/Cas9应用中的一些限制。本文综述了近两年来对CRISPR/Cpf1的研究进展和应用,并对其应用前景和发展方向进行了展望。     

Biocommunication and natural genome editing

The biocommunicative approach investigates communication processes within and among cells, tissues, organs and organisms as sign-mediated interactions, and nucleotide sequences as code, i.e. language-like text, which follows in parallel three kinds of rules: combinatorial (syntactic), context-sensitive (pragmatic), and content-specific (semantic). Natural genome editing from a biocommunicative perspective is competent agent-driven generation and integration of meaningful nucleotide sequences into pre-existing genomic content arrangements and the ability to (re-)combine and (re-)regulate them according to context-dependent (i.e. adaptational) purposes of the host organism.     

Harnessing CRISPR-Cas for oomycete genome editing

Oomycetes are a group of microorganisms that include pathogens responsible for devastating diseases in plants and animals worldwide. Despite their importance, the development of genome editing techniques for oomycetes has progressed more slowly than for model microorganisms. Here, we review recent breakthroughs in clustered regularly interspaced short palindromic repeats (CRISPR)-Cas technologies that are expanding the genome editing toolbox for oomycetes – from the original Cas9 study to Cas12a editing, ribonucleoprotein (RNP) delivery, and complementation. We also discuss some of the challenges to applying CRISPR-Cas in oomycetes and potential ways to overcome them. Advances in CRISPR-Cas technologies are being used to illuminate the biology of oomycetes, which ultimately can guide the development of tools for managing oomycete diseases.     

Programme OECD conference on genome editing

Transgenic Research -     

Trait stacking via targeted genome editing

Modern agriculture demands crops carrying multiple traits. The current paradigm of randomly integrating and sorting independently segregating transgenes creates severe downstream breeding challenges. A versatile, generally applicable solution is hereby provided: the combination of high‐efficiency targeted genome editing driven by engineered zinc finger nucleases (ZFNs) with modular ‘trait landing pads’ (TLPs) that allow ‘mix‐and‐match’, on‐demand transgene integration and trait stacking in crop plants. We illustrate the utility of nuclease‐driven TLP technology by applying it to the stacking of herbicide resistance traits. We first integrated into the maize genome an herbicide resistance gene, pat, flanked with a TLP (ZFN target sites and sequences homologous to incoming DNA) using WHISKERS?‐mediated transformation of embryogenic suspension cultures. We established a method for targeted transgene integration based on microparticle bombardment of immature embryos and used it to deliver a second trait precisely into the TLP via cotransformation with a donor DNA containing a second herbicide resistance gene, aad1, flanked by sequences homologous to the integrated TLP along with a corresponding ZFN expression construct. Remarkably, up to 5% of the embryo‐derived transgenic events integrated the aad1 transgene precisely at the TLP, that is, directly adjacent to the pat transgene. Importantly and consistent with the juxtaposition achieved via nuclease‐driven TLP technology, both herbicide resistance traits cosegregated in subsequent generations, thereby demonstrating linkage of the two independently transformed transgenes. Because ZFN‐mediated targeted transgene integration is becoming applicable across an increasing number of crop species, this work exemplifies a simple, facile and rapid approach to trait stacking.     

艰难梭菌基因编辑技术研究进展

艰难梭菌Clostridioesdifficile是一种革兰氏阳性、产芽孢、专性厌氧细菌,是医院相关性腹泻的主要病原体。近年来,随着强毒株的出现(如核糖体027型),其流行性与致死率逐年上升,因此对艰难梭菌生理、生化特征及致病机制的研究受到广泛重视。艰难梭菌生理、生化特征及致病机制研究又以建立其稳定、高效的基因编辑方法为必要前提。借助基因编辑工具,研究者可以扰动艰难梭菌核心生物学过程,在分子水平研究其分子致病机制。如Clos Tron技术在艰难梭菌毒素A (Toxin A)和毒素B (Toxin B)与其致病力关系的研究中起到了关键作用。文中以时间为主线综述了艰难梭菌基因编辑技术的发展历程和最新进展,并对艰难梭菌基因编辑技术未来的研究方向进行展望。     

Expanding genome capacity via RNA editing

RNA editing, which results in the creation of RNA molecules that differ from the template from which they were made, is a highly specific process. Alterations include converting one base to another, removal of one nucleotide and substitution of another, deletion of encoded residues, and insertion of non-templated nucleotides. Such changes have marked effects on gene expression, ranging from defined amino acid changes to the de novo creation of entire open reading frames. Editing can be regulated in a developmental or tissue-specific manner, and is likely to play a role in the etiology of human disease.     

2017基因组编辑专刊序言

基因组编辑技术,作为一项生物医学领域的革新技术,已经在动物、植物和微生物基因组改造中得到了广泛的应用。以CRISPR/Cas9为主导的基因组编辑技术掀起了基因组编辑的浪潮,在功能基因组学、遗传改良育种、遗传病治疗等研究中展示出其极大的价值与潜力。本专刊报道了基因组编辑技术的总体状况、在相关领域的基础与应用研究、该技术当前存在的优缺点以及未来展望等。     

Current and future editing reagent delivery systems for plant genome editing

Many genome editing tools have been developed and new ones are anticipated; some have been extensively applied in plant genetics, biotechnology and breeding, especially the CRISPR/Cas9 system. These technologies have opened up a new era for crop improvement due to their precise editing of user-specified sequences related to agronomic traits. In this review, we will focus on an update of recent developments in the methodologies of editing reagent delivery, and consider the pros and cons of current delivery systems. Finally, we will reflect on possible future directions.