The aphelids (phylum Aphelida) are phagotrophic parasitoids of algae and represent the most basal branch in superphylum Opisthosporidia, which contains the Microsporidia, Rozellosporidia and Aphelida. Being the closest group to traditional fungi, the aphelids should have ancestral features of both phyla. As in chytrids and other zoosporic fungi, the structure of zoospores is the most informative and important morphological feature for the phylogeny and taxonomy of aphelids. Though a general zoospore description exists for some aphelid species, their flagellar apparatus (kinetid) structure, which contains pivotal taxonomic and phylogenetic characters, has not been studied. Here we represent the kinetid structure in two genera, Aphelidium and Paraphelidium, and demonstrate independent reduction in the kinetid in each genus. The kinetid‐mitochondrion connection found in Aphelidium and Paraphelidium is rare for opisthokonts in general, but present in the most basal branches of Fungi and Opisthosporidia. We suggest, therefore, that this connection represents an ancestral character for both these phyla.

中文翻译：

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Aphelidium 和 Paraphelidium (Aphelida) 的动力学结构表明真菌和后孢子虫的共同祖先的特征

aphelids (phylum Aphelida) 是藻类的吞噬性寄生物，是 Opisthosporidia 超门中最基础的分支，包括 Microsporidia、Rozellosporidia 和 Aphelida。作为与传统真菌最接近的群体，aphelids 应该具有两个门的祖先特征。与壶菌和其他游动孢子真菌一样，游动孢子的结构是蚜虫的系统发育和分类学中最有信息和最重要的形态特征。尽管对于某些 aphelid 物种存在一般的游动孢子描述，但尚未研究它们的鞭毛器（动能）结构，其中包含关键的分类学和系统发育特征。在这里，我们代表了两个属（Aphelidium 和 Paraphelidium）的动力学结构，并展示了每个属中动力学的独立减少。在 Aphelidium 和 Paraphelidium 中发现的动力学 - 线粒体连接对于一般的反角动物来说是罕见的，但存在于真菌和反孢子的最基部分支中。因此，我们建议这种联系代表了这两个门的祖先特征。