| 1 | Double knock-in pig models with elements of binary Tet-On and phiC31 integrase systems for controllable and switchable gene expression显示文摘Inducible expression systems are indispensable for precise regulation and in-depth analysis of biological process.Binary Tet-On system has been widely employed to regulate transgenic expression by doxycycline.Previous pig models with tetracycline regulatory elements were generated through random integration.This process often resulted in uncertain expression and unpredictable phenotypes,thus hindering their applications.Here,by precise knock-in of binary Tet-On 3G elements into Rosa26 and Hipp11 locus,respectively,a double knock-in reporter pig model was generated.We characterized excellent properties of this system for controllable transgenic expression both in vitro and in vivo.Two att P sites were arranged to flank the td Tomato to switch reporter gene.Single or multiple gene replacement was efficiently and faithfully achieved in fetal fibroblasts and nuclear transfer embryos.To display the flexible application of this system,we generated a pig strain with Dox-inducing h KRASexpression through phiC31 integrase-mediated cassette exchange.After eight months of Dox administration,squamous cell carcinoma developed in the nose,mouth,and scrotum,which indicated this pig strain could serve as an ideal large animal model to study tumorigenesis.Overall,the established pig models with controllable and switchable transgene expression system will provide a facilitating platform for transgenic and biomedical research. | Qin Jin Xiaoyu Yang Shixue Gou Xiaoyi Liu Zhenpeng Zhuang Yanhui Liang Hui Shi Jiayuan Huang Han Wu Yu Zhao Zhen Ouyang Quanjun Zhang Zhaoming Liu Fangbing Chen Weikai Ge Jingke Xie Nan Li Chengdan Lai Xiaozhu Zhao Jiaowei Wang Meng Lian Lei Li Longquan Quan Yinghua Ye Liangxue Lai Kepin Wang | 2022 | Science China(Life Sciences)2022，65，11： | 1 |
| 2 | Base editors:development and applications in biomedicine显示文摘Base editor(BE)is a gene-editing tool developed by combining the CRISPR/Cas system with an individual deaminase,enabling precise single-base substitution in DNA or RNA without generating a DNA double-strand break(DSB)or requiring donor DNA templates in living cells.Base editors offer more precise and secure genome-editing effects than other conventional artificial nuclease systems,such as CRISPR/Cas9,as the DSB induced by Cas9 will cause severe damage to the genome.Thus,base editors have important applications in the field of biomedicine,including gene function investigation,directed protein evolution,genetic lineage tracing,disease modeling,and gene therapy.Since the development of the two main base editors,cytosine base editors(CBEs)and adenine base editors(ABEs),scientists have developed more than 100 optimized base editors with improved editing efficiency,precision,specificity,targeting scope,and capacity to be delivered in vivo,greatly enhancing their application potential in biomedicine.Here,we review the recent development of base editors,summarize their applications in the biomedical field,and discuss future perspectives and challenges for therapeutic applications. | Yanhui Liang Fangbing Chen Kepin Wang Liangxue Lai | 2023 | Frontiers of Medicine2023，17，3： | 0 |
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