title: New phylogenomic and comparative analyses provide corroborating evidence that Myxozoa is Cnidaria.
abstract: Myxozoa, a diverse group of morphologically simplified endoparasites, are well known fish parasites causing substantial economic losses in aquaculture. Despite active research, the phylogenetic position of Myxozoa remains ambiguous. After obtaining the genome and transcriptome data of the myxozoan Thelohanellus kitauei, we examined the phylogenetic position of Myxozoa from three different perspectives. First, phylogenomic analyses with the newly sequenced genomic data strongly supported the monophyly of Myxozoa and that Myxozoa is sister to Medusozoa within Cnidaria. Second, we detected two homologs to cnidarian-specific minicollagens in the T. kitauei genome with molecular characteristics similar to cnidarian-specific minicollagens, suggesting that the minicollagen homologs in T. kitauei may have functions similar to those in Cnidaria and that Myxozoa is Cnidaria. Additionally, phylogenetic analyses revealed that the minicollagens in myxozoans and medusozoans have a common ancestor. Third, we detected 11 of the 19 proto-mesodermalgenes in the T. kitauei genome, which were also present in the cnidarian Hydra magnipapillata, indicating Myxozoa is within Cnidaria. Thus, our results robustly support Myxozoa as a derived cnidarian taxon with an affinity to Medusozoa, helping to understand the diversity of the morphology, development and life cycle of Cnidaria and its evolution.
authors.affiliation: Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; Department of Pathogenic Biology, School of Medicine, Jianghan University, Wuhan 430056, China. Electronic address: fengjm@ihb.ac.cn.
authors.forename: Jin-Mei
authors.initials: JM
authors.lastname: Feng
authors.affiliation: Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China. Electronic address: njauxiongjie@163.com.
authors.forename: Jie
authors.initials: J
authors.lastname: Xiong
authors.affiliation: Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China. Electronic address: zhangjy@ihb.ac.cn.
authors.forename: Jin-Yong
authors.initials: JY
authors.lastname: Zhang
authors.affiliation: Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: yangyalin@caas.cn.
authors.forename: Ya-Lin
authors.initials: YL
authors.lastname: Yang
authors.affiliation: Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: binyao@caas.cn.
authors.forename: Bin
authors.initials: B
authors.lastname: Yao
authors.affiliation: Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: zhou_zg@msn.com.
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China. Electronic address: miaowei@ihb.ac.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Miao
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003063:Cnidaria / Q000145:classification*; D003094:Collagen / Q000235:genetics; D023281:Genomics; D008969:Molecular Sequence Data; D055764:Myxozoa / Q000145:classification*; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D059467:Transcriptome
chemical_list: D003094:Collagen
keywords: Cnidaria; Comparative analysis; Myxozoa; Phylogenomic analysis; Thelohanellus kitauei