随着微藻资源的开发应用，基因组定向改造技术已经成为选育高经济价值藻类新品系的重要途径。但到目前为止，真核微藻的基因组定向改造体系尚不成熟，如何实现核基因组特定区域DNA的插入、敲除和替换已经成为微藻基因工程改造的瓶颈。本项目以莱茵衣藻为对象，拟通过敲除Ku蛋白降低NHEJ和导入可“按需”表达Red重组酶提高HR效率的策略，建立莱茵衣藻基因组同源重组定向改造系统，并进一步分析关键蛋白在核基因编辑中的角色及相互关系，认识衣藻同源重组编辑技术的细胞内在过程变化，发现内源Ku蛋白和外源重组蛋白对同源重组其他关键基因影响的分子机理。该研究体现了微藻应用与基础科学研究的原始创新性，为微藻优良性状性品系选育及微藻产业发展提供重要的理论基础与技术保障。

In the developmental application of microalgae resources, the targeted genome modification technique has become an important approach in breeding new lines of microalgae with high economic value. This technique, however, has not been well established. Limitations in precise DNA insertion, knockout or replacement in nuclear genome are still the main of bottlenecks in microalgae genetic engineering. In order to solve this problem, using Chlamydomonas reinhardtii as the representative of algae，we will Knockout of the Ku protein and import “on demand” expressed Red recombinase to improve the efficiency of the homologous recombination and to establish targeted genome modification in Chlamydomonas reinhardtii. Moreover, we shall further analysis of the roles and correlations of key proteins in the nuclear genome editing, reveal cell intrinsic changes resulted from Chlamydomonas homologous recombination editing technology, and discover the molecular mechanism of the effect of endogenous Ku protein and exogenous recombinant protein on other key genes of homologous recombination. This research reflects the original innovation of microalgal application and basic science research, and provides important theoretical basis and technical support for the breeding of microalgae and the development of microalgae industry.