CRISPR-Cas系统是广泛存在于细菌和古菌中的防御系统。基于该系统开发的基因组编辑工具已在大量物种中实现靶向编辑。目前应用最多的是CRISPR-Cas9和CRISPR-Cas12a基因组编辑工具,但它们的蛋白大小均超过1000个氨基酸,不利于递送。来自...CRISPR-Cas系统是广泛存在于细菌和古菌中的防御系统。基于该系统开发的基因组编辑工具已在大量物种中实现靶向编辑。目前应用最多的是CRISPR-Cas9和CRISPR-Cas12a基因组编辑工具,但它们的蛋白大小均超过1000个氨基酸,不利于递送。来自转座子家族的TnpB和IscB蛋白(大小约400个氨基酸)分别被认为是Cas12和Cas9的祖先蛋白,但其功能直到最近才被解析。它们被统称为专性移动元件引导活性(obligate mobile element-guided activity, OMEGA)蛋白,其引导RNA被称为ωRNA。此后,OMEGA系统成为了基因编辑领域的研究热点之一。OMEGA系统在三域生物中都有广泛分布,而且种类多样。对OMEGA系统的深入研究,将有助于开发精简、高效、安全的新型基因组编辑工具。本文围绕OMEGA系统的发现历程、结构特点、作用机制和在基因组编辑中的应用展开介绍,为新型基因组编辑工具的开发和优化提供参考。展开更多
The widely used clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated nuclease(Cas)system is thought to have evolved from IS200/IS605 transposons.TnpB proteins,encoded by one type of IS20...The widely used clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated nuclease(Cas)system is thought to have evolved from IS200/IS605 transposons.TnpB proteins,encoded by one type of IS200/IS605 transposon,are considered to be the evolutionary ancestors of Cas12 nucleases,which have been engineered to function as RNA-guided DNA endonucleases for genome editing in bacteria and human cells.TnpB nucleases,which are smaller than Cas nucleases,have been engineered for use in genome editing in animal systems,but the feasibility of this approach in plants remained unknown.Here,we obtained stably transformed genome-edited mutants in rice(Oryza sativa)by adapting three recently identified TnpB genome editing vectors,encoding distinct TnpB nucleases(ISAam1,ISDra2,and ISYmu1),for use in plants,demonstrating that the hypercompact TnpB proteins can effectively edit plant genomes.ISDra2 and ISYmu1 precisely edited their target sequences,with no off-target mutations detected,showing that TnpB transposon nucleases are suitable for development into a new genome editing tool for plants.Future modifications improving the genome-editing efficiency of the TnpB system will facilitate plant functional studies and breeding programs.展开更多
文摘CRISPR-Cas系统是广泛存在于细菌和古菌中的防御系统。基于该系统开发的基因组编辑工具已在大量物种中实现靶向编辑。目前应用最多的是CRISPR-Cas9和CRISPR-Cas12a基因组编辑工具,但它们的蛋白大小均超过1000个氨基酸,不利于递送。来自转座子家族的TnpB和IscB蛋白(大小约400个氨基酸)分别被认为是Cas12和Cas9的祖先蛋白,但其功能直到最近才被解析。它们被统称为专性移动元件引导活性(obligate mobile element-guided activity, OMEGA)蛋白,其引导RNA被称为ωRNA。此后,OMEGA系统成为了基因编辑领域的研究热点之一。OMEGA系统在三域生物中都有广泛分布,而且种类多样。对OMEGA系统的深入研究,将有助于开发精简、高效、安全的新型基因组编辑工具。本文围绕OMEGA系统的发现历程、结构特点、作用机制和在基因组编辑中的应用展开介绍,为新型基因组编辑工具的开发和优化提供参考。
文摘The widely used clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated nuclease(Cas)system is thought to have evolved from IS200/IS605 transposons.TnpB proteins,encoded by one type of IS200/IS605 transposon,are considered to be the evolutionary ancestors of Cas12 nucleases,which have been engineered to function as RNA-guided DNA endonucleases for genome editing in bacteria and human cells.TnpB nucleases,which are smaller than Cas nucleases,have been engineered for use in genome editing in animal systems,but the feasibility of this approach in plants remained unknown.Here,we obtained stably transformed genome-edited mutants in rice(Oryza sativa)by adapting three recently identified TnpB genome editing vectors,encoding distinct TnpB nucleases(ISAam1,ISDra2,and ISYmu1),for use in plants,demonstrating that the hypercompact TnpB proteins can effectively edit plant genomes.ISDra2 and ISYmu1 precisely edited their target sequences,with no off-target mutations detected,showing that TnpB transposon nucleases are suitable for development into a new genome editing tool for plants.Future modifications improving the genome-editing efficiency of the TnpB system will facilitate plant functional studies and breeding programs.
