Data from: Phylogenomic diversity of archigregarine apicomplexans

AbstractGregarines are a large and diverse subgroup of Apicomplexa, a lineage of obligate animal symbionts including pathogens like Plasmodium, the malaria parasite. Unlike Plasmodium, however, gregarines are poorly studied, despite the fact that as early-branching apicomplexans they are crucial to our understanding of the origin and evolution of all apicomplexans and their parasitic lifestyle. Exemplifying this, the earliest branch of gregarines, the archigregarines, are particularly poorly studied: around 80 species have been described from marine invertebrates, but almost all of them were assigned to a single genus, Selenidium. Most are known only from light micrographs and largely unresolved rDNA phylogenies, where they exhibit a great deal of sequence variation, but fall into at least five subclades. To resolve the relationships within archigregarines, we sequenced 12 single-cell transcriptomes from species representing all four known subclades, as well as one blastogregarine (which frequently branch with Selenidium). A 190-gene phylogenomic tree confirmed fourmaximally-supported individual clades of archigregarines and blastogregarines. These clades are discrete and distantly related, and also correlate with host identity. We propose the establishment of three novel genera of archigregarines to reflect their phylogenetic diversity and host range, and nine novel species isolated from a range of marine invertebrates.摘要：簇虫（Gregarines）是顶复门（Apicomplexa）中一个庞大且多样的类群，顶复门是一类专性动物共生生物谱系，包含疟原虫属（Plasmodium，即疟疾寄生虫）等致病菌。然而与疟原虫不同，簇虫的研究程度较低——尽管作为早期分化的顶复门生物，它们对于我们理解所有顶复门生物的起源、演化及其寄生生活方式至关重要。其中最具代表性的是，簇虫中最早分化的分支原簇虫亚目（archigregarines）的研究尤为匮乏：目前已从海洋无脊椎动物中描述了约80个物种，但几乎所有物种都被归入单一的硒定虫属（Selenidium）。这类生物大多仅通过光学显微图像（light micrographs）和分辨率有限的核糖体DNA（rDNA）系统发育树被认知，其序列差异极大，但至少可划分为5个演化支。为解析原簇虫亚目内部的演化关系，我们对代表已知全部4个演化支的物种以及1种常与硒定虫属聚类的芽簇虫类（blastogregarines）进行了12个单细胞转录组（single-cell transcriptomes）测序。基于包含190个基因的系统发育基因组树，我们确认原簇虫亚目与芽簇虫类存在4个支持率最高的独立演化支。这些演化支彼此独立且亲缘关系较远，同时与宿主类群具有相关性。基于此，我们提议建立3个原簇虫亚目新属，以反映其系统发育多样性与宿主范围，并描述9个分离自多种海洋无脊椎动物的新物种。