Abstract：
Several hundred ciliate species live in animals\' guts as a part of their microbiome. Among them, Muniziella cunhai (Trichostomatia, Pycnotrichidae), the largest described ciliate, is found exclusively associated with Hydrochoerus hydrochaeris (capybara), the largest known rodent reaching up to 90 kg. Here, we present the sequence, structural and functional annotation of this giant microeukaryote macronuclear genome and discuss its phylogenetic placement. The 85 Mb genome is highly AT rich (GC content 25.71 %) and encodes a total of 11 397 protein-coding genes, of which 2793 could have their functions predicted with automated functional assignments. Functional annotation showed that M. cunhai can digest recalcitrant structural carbohydrates, non-structural carbohydrates, and microbial cell walls, suggesting a role in diet metabolization and in microbial population control in the capybara\'s intestine. Moreover, the phylogenetic placement of M. cunhai provides insights on the origins of gigantism in the subclass Trichostomatia.
摘要：
数百种纤毛虫物种作为其微生物组的一部分生活在动物的肠道中。其中,Muniziellacunhai(Trichostomatia,pycnotrichidae），最大的纤毛虫，被发现仅与Hydrochoerushydrochaeris（水豚）有关，已知最大的啮齿动物达到90公斤。这里,我们呈现序列，这个巨大的微真核生物大核基因组的结构和功能注释，并讨论其系统发育位置。85Mb基因组富含AT（GC含量25.71％），总共编码11397个蛋白质编码基因，其中2793人可以用自动功能分配来预测他们的功能。功能注释表明，M.cunhai可以消化顽固的结构碳水化合物，非结构性碳水化合物，和微生物细胞壁，提示在水痘肠道的饮食代谢和微生物种群控制中的作用。此外，M.cunhai的系统发育位置提供了有关Trichostoatia亚类巨人症起源的见解。
