Belyaev Artem O, Karpov Sergey A, Keeling Patrick J, Tikhonenkov Denis V
Papanin Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Yaroslavl, Russia.
Zoological Institute, Russian Academy of Sciences, Saint Petersburg, Russia.
Open Biol. 2024 Dec;14(12):240158. doi: 10.1098/rsob.240158. Epub 2024 Dec 18.
The recently discovered Provora supergroup has primarily been examined to determine their phylogenomic position in the eukaryotic tree. Their morphology is more poorly studied, and here we focus on their cellular organization and how it compares with that of other supergroups. These small eukaryovorous flagellates exhibit several ultrastructural features that are also found in a subset of taxa from a wide variety of deep-branching lineages (Stramenopiles, Alveolata, Hemimastigophora, Malawimonadidae, Discoba and Metamonada), including vesicles beneath the plasmalemma, two opposing vanes on the flagella, a ventral feeding groove and a fibrillar system resembling the excavate type. Additionally, we identified four main microtubular roots (r1-r4) and a singlet root between r1 and r2, which support the strong feeding apparatus resembling 'jaws'. Their unique extrusive organelles (ampulosomes) have a similar organization to Hemimastigophora extrusomes, but most of their cell characteristics most closely resemble features of the TSAR + Haptista grouping. We also describe a new species, sp. nov., and highlight features of its feeding behaviour, which can be so aggressive as to result in cannibalism.
最近发现的普罗沃拉超群主要是为了确定它们在真核生物树中的系统基因组位置而进行研究的。对它们形态的研究较少,在这里我们关注它们的细胞组织以及它与其他超群的细胞组织如何比较。这些小型真核食鞭毛虫表现出一些超微结构特征,这些特征也存在于来自各种深分支谱系(不等鞭毛类、囊泡虫类、半鞭毛虫类、马拉维单胞菌科、盘状鞭毛虫类和元毛虫类)的部分分类群中,包括质膜下方的囊泡、鞭毛上的两个相对的叶片、一个腹侧进食沟和一个类似于盘状鞭毛虫类型的纤维系统。此外,我们确定了四个主要的微管根(r1 - r4)以及r1和r2之间的一个单根,它们支撑着类似“ jaws”的强大进食器官。它们独特的挤压细胞器(壶状体)与半鞭毛虫类的挤压细胞器具有相似的组织,但它们的大多数细胞特征与TSAR + 触滴虫类群的特征最为相似。我们还描述了一个新物种, 新种,并强调了其进食行为的特征,这种行为可能非常激进,以至于会导致同类相食。