A chromosome-level genome assembly for the paramylon-producing microalga Euglena gracilis
Zixi Chen, Yang Dong, Shengchang Duan, Jiayi He, Huan Qin, Chao Bian, Zhenfan Chen, Chenchen Liu, Chao Zheng, Ming‐Qing Du, Rao Yao, Chao Li, Panpan Jiang, Yun Wang, Shuangfei Li, Ning Xie, Ying Xu, Qiong Shi, Zhangli Hu, Anping Lei, Liqing Zhao, Jiangxin Wang
Abstract
Euglena gracilis (E. gracilis), pivotal in the study of photosynthesis, endosymbiosis, and chloroplast development, is also an industrial microalga for paramylon production. Despite its importance, E. gracilis genome exploration faces challenges due to its intricate nature. In this study, we achieved a chromosome-level de novo assembly (2.37 Gb) using Illumina, PacBio, Bionano, and Hi-C data. The assembly exhibited a contig N50 of 619 Kb and scaffold N50 of 1.12 Mb, indicating superior continuity. Approximately 99.83% of the genome was anchored to 46 chromosomes, revealing structural insights. Repetitive elements constituted 58.84% of the sequences. Functional annotations were assigned to 39,362 proteins, enhancing interpretative power. BUSCO analysis confirmed assembly completeness at 80.39%. This first high-quality E. gracilis genome offers insights for genetics and genomics studies, overcoming previous limitations. The impact extends to academic and industrial research, providing a foundational resource.