Reporters learned from the Institute of Zoology of the Chinese Academy of Sciences on the 9th that the new technology of retrotransposon gene engineering developed by the researchers Li Wei and Zhou Qi of the Institute is the first time to achieve precise gene writing using RNA as a vector, which is expected to bring more efficient, safer and low-cost new treatment methods for diseases such as genetic diseases and tumors, and provide a basis for the development of a new generation of gene therapy. The relevant results are published online in the journal Cell. At present, technological advancements represented by CRISPR gene editing technology have basically achieved precise editing at the single base and short sequence scales. "However, how to achieve efficient and precise integration of large fragments of gene scale DNA into the genome in response to the needs of application scenarios is still an urgent challenge that needs to be overcome in the entire field of genetic engineering," said Li Wei, co corresponding author of the paper. In response to this major technological challenge, various gene writing technologies have been developed, but most of these technologies use DNA as a medium. In practical medical applications, DNA vectors face many challenges such as high immunogenicity and the risk of random integration in the genome. In contrast, RNA vectors have the characteristics of lower immunogenicity, effective delivery by non viral vectors, rapid degradation within cells, and no risk of random integration, which can effectively address the challenges faced by DNA vectors. "Therefore, RNA mediated precision writing technology for large fragments has significant advantages in terms of safety and delivery," said Li Wei. Based on the R2 retrotransposon system that exists in nature, researchers have developed an R2 retrotransposon tool for precise writing of large fragment genes using RNA as a medium, combining genomic data mining and macromolecular engineering modification. This tool can efficiently and accurately integrate large fragments of genes from various mammalian cells, successfully achieving precise writing of functional genes mediated by RNA in various mammalian genomes. (Lai Xin She)