Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic.
Institute of Parasitology, Biology Centre CAS, České Budějovice, Czech Republic.
Proc Biol Sci. 2024 Jan 31;291(2015):20232563. doi: 10.1098/rspb.2023.2563.
(Cestoda: Diphyllobothriidae) is an emerging model organism for studies on parasite population biology and host-parasite interactions. However, a well-resolved genome and catalogue of its gene content has not been previously developed. Here, we present the first genome assembly of , based on Oxford Nanopore Technologies, Illumina and Omni-C sequencing methodologies. We use transcriptome profiling to compare plerocercoid larvae and adult worms and identify differentially expressed genes (DEGs) associated with these life stages. The genome assembly is 775.3 mega (M)bp in size, with scaffold N50 value of 118 Mbp and encodes 27 256 predicted protein-coding sequences. Over 60% of the genome consists of repetitive sequences. Synteny analyses showed that the 10 largest scaffolds representing 75% of the genome display high correspondence to full chromosomes of cyclophyllidean tapeworms. Mapping RNA-seq data to the new reference genome, we identified 3922 differentially expressed genes in adults compared with plerocercoids. Gene ontology analyses revealed over-represented genes involved in reproductive development of the adult stage (e.g. sperm production) and significantly enriched DEGs associated with immune evasion of plerocercoids in their fish host. This study provides the first insights into the molecular biology of and provides the most highly contiguous assembly to date of a diphyllobothriid tapeworm useful for population and comparative genomic investigations of parasitic flatworms.
（膜壳绦虫科）是一种新兴的寄生虫种群生物学和宿主-寄生虫相互作用研究模式生物。然而，其基因组和基因内容目录尚未得到很好的解析。在这里，我们基于牛津纳米孔技术、Illumina 和 Omni-C 测序方法，首次提供了 的基因组组装。我们使用转录组谱分析比较了细颈囊尾蚴幼虫和成虫，并鉴定了与这些生命阶段相关的差异表达基因 (DEG)。基因组组装大小为 775.3 兆碱基 (Mbp)，支架 N50 值为 118 Mbp，编码 27256 个预测的蛋白质编码序列。超过 60%的基因组由重复序列组成。同线性分析表明，代表基因组 75%的 10 个最大支架与环片吸虫的完整染色体具有高度对应关系。将 RNA-seq 数据映射到新的参考基因组，我们在成虫与细颈囊尾蚴相比时鉴定出 3922 个差异表达基因。基因本体论分析显示，与生殖发育相关的基因过度表达（例如精子生成），以及与幼虫在其鱼类宿主中免疫逃避相关的显著富集差异表达基因。本研究首次深入了解了 的分子生物学，并提供了迄今为止最连续的膜壳绦虫基因组组装，可用于寄生虫扁形虫的种群和比较基因组研究。
