Department of Laboratory Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China.
Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark.
Front Cell Infect Microbiol. 2022 Feb 2;12:797017. doi: 10.3389/fcimb.2022.797017. eCollection 2022.
The alga is the only chlorophyte known to be involved in a series of clinically relevant opportunistic infections in humans and animals, namely, protothecosis. Most pathogenic cases in humans are caused by . In order to investigate the evolution of and the genetic basis for its pathogenicity, the genomes of two strains S1 and S931 were sequenced using Nanopore long-read and Illumina short-read technologies. The mitochondrial, plastid, and nuclear genomes were assembled and annotated including a transcriptomic data set. The assembled nuclear genome size was 17.57 Mb with 19 contigs and 17.45 Mb with 26 contigs for strains S1 and S931, respectively. The number of predicted protein-coding genes was approximately 5,700, and more than 96% of the genes could be annotated with a gene function. A total of 2,798 gene families were shared between the five currently available genomes. According to the phylogenetic analysis, the genus of was classified in the same clade with and diverged from ~500 million years ago (Mya). A total of 134 expanded genes were enriched in several pathways, mostly in metabolic pathways, followed by biosynthesis of secondary metabolites and RNA transport. Comparative analysis demonstrated more than 96% consistency between the two herein sequenced strains. At present, due to the lack of sufficient understanding of the biology and pathogenicity, the diagnosis rate of protothecosis is much lower than the actual infection rate. This study provides an in-depth insight into the genome sequences of two strains of isolated from the clinic to contribute to the basic understanding of this alga and explore future prevention and treatment strategies.
该藻是唯一已知与人类和动物一系列临床相关机会性感染有关的绿藻，即原绿球藻病。大多数人类致病性病例由引起。为了研究和的进化及其致病性的遗传基础，使用 Nanopore 长读和 Illumina 短读技术对两个菌株 S1 和 S931 的基因组进行了测序。组装和注释了线粒体、质体和核基因组，包括转录组数据集。组装的核基因组大小分别为 17.57 Mb 和 19 个 contigs，以及 17.45 Mb 和 26 个 contigs。预测的蛋白编码基因数量约为 5700 个，超过 96%的基因可以用基因功能注释。共有 2798 个基因家族在现有的 5 个 基因组之间共享。根据系统发育分析，属与和同属于一个分支，与分化于约 5 亿年前（Mya）。总共在 134 个扩展基因中富集了多个途径，主要是在代谢途径中，其次是次生代谢物的生物合成和 RNA 运输。比较分析表明，这两个测序菌株之间有超过 96%的一致性。目前，由于对原绿球藻生物学和致病性的了解不足，原绿球藻病的诊断率远低于实际感染率。本研究深入了解了从临床分离的两个菌株的基因组序列，有助于对该藻类的基础认识，并探索未来的预防和治疗策略。
