著者
Yazaki Euki Ishikawa Sohta A. Kume Keitaro Kumagai Akira Kamaishi Takashi Tanifuji Goro Hashimoto Tetsuo Inagaki Yuji
出版者
日本遺伝学会
雑誌
Genes & Genetic Systems
巻号頁・発行日
2017
被引用文献数
25

<p>All members of the order Trypanosomatida known to date are parasites that are most likely descendants of a free-living ancestor. Trypanosomatids are an excellent model to assess the transition from a free-living to a parasitic lifestyle, because a large amount of experimental data has been accumulated for well-studied members that are harmful to humans and livestock (<i>Trypanosoma</i> spp. and <i>Leishmania</i> spp.). However, recent advances in our understanding of the diversity of trypanosomatids and their close relatives (i.e., members of the class Kinetoplastea) have suggested that the change in lifestyle took place multiple times independently from that which gave rise to the extant trypanosomatid parasites. In the current study, transcriptomic data of two parasitic kinetoplastids belonging to orders other than Trypanosomatida, namely <i>Azumiobodo hoyamushi</i> (Neobodonida) and <i>Trypanoplasma borreli</i> (Parabodonida), were generated. We re-examined the transition from a free-living to a parasitic lifestyle in the evolution of kinetoplastids by combining (i) the relationship among the five orders in Kinetoplastea and (ii) that among free-living and parasitic species within the individual orders. The former relationship was inferred from a large-scale multigene alignment including the newly generated data from <i>Azumiobodo</i> and <i>Trypanoplasma</i>, as well as the data from another parasitic kinetoplastid, <i>Perkinsela</i> sp., deposited in GenBank; and the latter was inferred from a taxon-rich small subunit ribosomal DNA alignment. Finally, we discuss the potential value of parasitic kinetoplastids identified in Parabodonida and Neobodonida for studying the evolutionary process that turned a free-living species into a parasite.</p>