原藻是唯一已知参与人类和动物一系列临床相关机会性感染的叶绿素,即,原生质体病.人类中的大多数致病病例是由无绿藻引起的。为了研究无绿藻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wickerhamii菌株S1和S931的基因组进行了测序。线粒体,质体,和核基因组被组装和注释,包括转录组数据集。对于菌株S1和S931,组装的核基因组大小分别为17.57Mb,19个重叠群和17.45Mb,26个重叠群。预测的蛋白质编码基因的数量约为5,700,超过96%的基因可以用基因功能进行注释。共有2,798个基因家族在五个目前可用的无绿藻基因组之间共享。根据系统发育分析,原藻属与原藻属属于同一进化枝,与5亿年前的小球藻(Mya)不同。共有134个扩增的基因在几个途径中富集,主要是在代谢途径中,其次是次级代谢产物的生物合成和RNA转运。比较分析证明本文测序的两个菌株之间超过96%的一致性。目前,由于缺乏对无绿藻生物学和致病性的充分了解,原虫病的诊断率远低于实际感染率。这项研究提供了深入了解从临床分离的两株威克哈姆氏杆菌的基因组序列,有助于对这种藻类的基本认识,并探索未来的预防和治疗策略。
The Prototheca 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 Prototheca wickerhamii. In order to investigate the evolution of Prototheca and the genetic basis for its pathogenicity, the genomes of two P. wickerhamii 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 Prototheca genomes. According to the phylogenetic analysis, the genus of Prototheca was classified in the same clade with A. protothecoides and diverged from Chlorella ~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 Prototheca 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 P. wickerhamii isolated from the clinic to contribute to the basic understanding of this alga and explore future prevention and treatment strategies.