Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
Protist 10,000 Genomics Project (P10K) Consortium, Wuhan, China.
Sci Data. 2024 Mar 28;11(1):323. doi: 10.1038/s41597-024-03142-1.
Balantidium ctenopharyngodoni is identified as the sole ciliate species that exclusively resides within the hindgut of grass carp with high prevalence and intensity. In this study, the successful cultivation of B. ctenopharyngodoni enabled us to collect enough cells for genome sequencing. Consequently, we acquired a high-quality genome assembly spanning 68.66 Mb, encompassing a total of 22,334 nanochromosomes. Furthermore, we predicted 29,348 protein-coding genes, and 95.5% of them was supported by the RNA-seq data. The trend of GC content in the subtelomeric regions of single-gene chromosomes was similar to other ciliates containing nanochromosomes. A large number of genes encoding carbohydrate-binding modules with affinities for starch and peptidoglycans was identified. The identification of mitochondrion-related organelles (MROs) within genome indicates its well-suited adaptation to the anaerobic conditions in the hindgut environment. In summary, our results will offer resources for understanding the genetic basis and molecular adaptations of balantidia to hindgut of herbivorous fish.
中华四膜虫是唯一一种专性寄生在草鱼后肠的纤毛虫，其感染率和感染强度都很高。本研究成功培养了中华四膜虫，收集到足够的细胞进行基因组测序。因此，我们获得了一个高质量的基因组组装，大小为 68.66Mb，共包含 22334 个纳米染色体。此外，我们预测了 29348 个蛋白质编码基因，其中 95.5%的基因得到了 RNA-seq 数据的支持。单基因染色体端粒区 GC 含量的趋势与其他含有纳米染色体的纤毛虫相似。鉴定出了大量编码对淀粉和肽聚糖具有亲和力的糖结合模块的基因。基因组中与线粒体相关的细胞器（MROs）的鉴定表明，它非常适合在后肠厌氧环境中生存。总之，我们的研究结果将为了解纤毛虫适应草食性鱼类后肠的遗传基础和分子适应机制提供资源。
