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Zhao W, Bu X, Zou H, Li W, Wu S, Li M, Wang G. The Genome of the Mitochondrion-Related Organelle in Cepedea longa, a Large Endosymbiotic Opalinid Inhabiting the Recta of Frogs. Int J Mol Sci 2022; 23:13472. [DOI: 10.3390/ijms232113472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 10/13/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022] Open
Abstract
Mitochondrion-related organelles (MROs) are loosely defined as degenerated mitochondria in anaerobic and microaerophilic lineages. Opalinids are commonly regarded as commensals in the guts of cold-blooded amphibians. It may represent an intermediate adaptation stage between the conventional aerobic mitochondria and derived anaerobic MROs. In the present study, we sequenced and analyzed the MRO genome of Cepedea longa. It has a linear MRO genome with large inverted repeat gene regions at both ends. Compared to Blastocystis and Proteromonas lacertae, the MRO genome of C. longa has a higher G + C content and repeat sequences near the central region. Although three Opalinata species have different morphological characteristics, phylogenetic analyses based on eight concatenated nad genes indicate that they are close relatives. The phylogenetic analysis showed that C. longa clustered with P. lacertae with strong support. The 18S rRNA gene-based phylogeny resolved the Opalinea clade as a sister clade to Karotomorpha, which then further grouped with Proteromonas. The paraphyly of Proteromonadea needs to be verified due to the lack of MRO genomes for key species, such as Karotomorpha, Opalina and Protoopalina. Besides, our dataset and analyses offered slight support for the paraphyly of Bigyra.
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Zhao W, Hu G, Ponce-Gordo F, Zou H, Li W, Wu S, Li M, Wang G. Morphological description of Opalina obtrigonoidea Metcalf, 1923 (Heterokonta, Opalinea) from Duttaphrynus melanostictus and evaluation of the ITS region as a suitable genetic marker for inter-species identification in Opalina. Parasitol Int 2020; 76:102103. [PMID: 32169658 DOI: 10.1016/j.parint.2020.102103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 03/03/2020] [Accepted: 03/08/2020] [Indexed: 11/25/2022]
Abstract
The redescription of Opalina obtrigonoidea Metcalf, 1923, collected from the rectum of the toads Duttaphrynus melanostictus, is presented in this paper based on detailed morphological information and molecular data. Our results revealed that O. obtrigonoidea varies greatly in body dimensions. Its morphological characteristics allow its differentiation from Opalina undulata. Surprisingly, we sequenced its SSU rDNA-ITS1-5.8S rDNA-ITS2-LSU rDNA (5' end) and found the SSU rDNA of O. obtrigonoidea is nearly identical to that of O. undulata. However, there are differences in both the ITS1 and ITS2 regions that allow their distinction and confirm the morphological differences. Our results indicate that O. obtrigonoidea and O. undulata are closely related species in which morphological and genetic markers have evolved at different speeds. Due to this, the SSU rDNA gene may not be a valid marker for inter-species identification in Opalina, but the ITS is a valid marker for differentiating species in this genus.
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Affiliation(s)
- Weishan Zhao
- State Key Laboratory of Freshwater Ecology and Biotechnology, and Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guangran Hu
- State Key Laboratory of Freshwater Ecology and Biotechnology, and Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Francisco Ponce-Gordo
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza Ramóny Cajal s/n, 28040 Madrid, Spain
| | - Hong Zou
- State Key Laboratory of Freshwater Ecology and Biotechnology, and Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Wenxiang Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, and Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Shangong Wu
- State Key Laboratory of Freshwater Ecology and Biotechnology, and Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Ming Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, and Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
| | - Guitang Wang
- State Key Laboratory of Freshwater Ecology and Biotechnology, and Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
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