CRISPR/Cas system provides as a powerful genome editing tool for elucidating the functions of gene elements and correcting genetic mutations. However, problems and challenges like in vivo delivery still existed in scientific and clinical application. We plan to solve the problem of delivery and use our newly developed delivery system for in vivo gene function screening. We will focus on the following studies: 1). Developing new gene editing tools with higher fidelity. 2). Solving the problem of in vivo delivery for gene editing tools. 3). High-throughput screening for functional genes and therapeutic targets in disease models.
1. Development of gene editing tools
CRISPR/Cas system has been widely used in various organisms for basic research and disease treatment. However, there are still many problems about this system. DNA double-strand breaks generated by Cas9 has the risk of inducing large fragment deletion and chromosome rearrangement, and base editor derivated from CRISPR/Cas has the risk of introducing random off-target edits. Therefore, we aim to optimize and develop new gene editing tools with higher accurary and fidelity using a novel directed evolution system.
Although gene therapy provides a rational treatment option for many genetic diseases, its development was hindered by several setbacks. The biggest challenge is to efficiently deliver gene editors to impaired organ/tissue. Therefore, we aim to find out more compact editing proteins from nature through computational biology, and then make editor optimization using directed evolution systems. We hope to overcome the obstacle for gene therapy by applying this system.

2. High-throughput gene screening by gene editing tools
Discovery or functional annotation of genes in different biological process is one of the most critical issues in life science. Traditional RNA interference (RNAi) could only perform gene knockdown screening, while CRISPR-based screening system could be successfully used in gene knockdown, knockout and activation screening. Currently, CRISPR-based screening is mainly carried out in cultured cells, which cannot simulate the complex environment in vivo. Therefore, we will perform high-throughput functional gene screening in vivo through AAV virus library to obtain new treatment targets.