Construction of genetically modified animal models

Genetically modified animal is an important tool for understanding gene functions in development and disease. The fact that non-human primates share highly similar physiological structure with human, makes them clinically significant for disease simulation, research and development of new drugs, as well as drug screening. Therefore, we construct disease models in non-human primates using various ways according to diseases’ distinctive features. With diseases caused by systemic gene deletion, we apply Cocktail method to edit gene at zygote phase, and successfully obtain fully functional both single and multiple gene knockout F0 mice and monkey, which can be used directly for phenotypical analysis. This achievement largely drives the establishment of non-human primate models and its standing in neuroscience and neuronal diseases.For those diseases which have same underlying mechanism but only show pathological response locally, we intend to infect adult animals with lentivirus to obtain disease models apace. In line with each characteristic of gene deletion, we choose the best fit gene edit method, options including CRISPR/Cas9 and single-base editor. As for gene knock-in models, we devise a homology-mediated end joining (HMEJ)-base strategy, that allows precise and efficient transgene integration to happen on both dividing and non-dividing cells. Accelerated reproduction of these knock-in monkeys obtained from HMEJ can be achieved with the help of testicular xenografting explored by SUN Qiang’s team from Suzhou Non-human Primate Facility, abundant F1 knock-in monkeys can be generated as fast as two years. Our goal for near future is to generate monkey disease models including PD, AD, ALS, DMD, RP, AS etc., monkey tool models including optogenetic models, neuro-specific Cre monkeys etc. We are certain that construction of these monkey models will push the boundary of our understanding towards diseases and their cures.

Gene Therapy

There are around 7000 genetic disorders we currently known of, most of them, however, don’t have corresponding medicine or effective treatment. Fortunately, the emergence and evolution of new gene editing techniques such as CRISPR-Cas9 and single base editing brings hope for a cure of these diseases. The distinguishing feature of gene editing technique is the precision it gives in performing site-directed mutagenesis, insertion, and deletion. It thereby treats diseases by modifying mutated loci on a molecular level. For this matter, we intend to first screen diseases that exhibit local pathological symptoms, next package gene editors into adeno associated virus, lastly infect tissues with this packaged virus to make gene therapy happen.

Off-target detection of gene editing

CRISPR/Cas9 is a new generation of gene editing tool that has been widely used. Since the appearance in 2012, it has aroused great attention for its efficiency and specificity. Scientists widely believe that clinical application of CRISPR/Cas9 and its derivatives will make great contribution to human health. However, the risk of off-target has been a serious concern since the advent of CRISPR/Cas9. The potential off-targets effects may cause many side effects including cancer if CRISPR/Cas9 and its derivatives are used for clinical application. Thus, a robust off-target detection method will be the key to the clinical application of CRISPR/Cas9 and its derivatives.