Small subunit ribosomal RNA and mitochondrial cytochrome c oxidase subunit 1 gene sequences of 21 strains of the parasitic scuticociliate Miamiensis avidus (Ciliophora, Scuticociliatia)
- 365 Downloads
The scuticociliate Miamiensis avidus is a histophagous parasite that causes high mortality in cultured marine fishes. Small subunit ribosomal RNA (SSU rRNA) and mitochondrial cytochrome c oxidase subunit 1 (cox1) genes were analyzed for 21 strains of M. avidus isolated from diseased olive flounder (Paralichthys olivaceus), ridged-eye flounder (Pleuronichthys cornutus), and spotted knifejaw (Oplegnathus fasciatus) in Korea and Japan (collected in 2003–2007). Analysis of SSU rRNA gene sequences (1,759 bp) indicates they are very conserved with less than 0.17% (3 nucleotides) differences suggesting that SSU rRNA are useful to identify M. avidus; however, the cox1 gene (900 bp) has higher variations with intraspecific divergences up to 5.67% (51 nucleotides). A distance tree of cox1 gene sequences based on a neighbor-joining analysis can separate 21 strains into five cox1 types (two heterogeneous clusters and three individual branches). The cox1-type matches with serotype of strains but do not reflect geographical origins, host species, or pathogenicity.
KeywordsCox1 Gene Gene Sequence Divergence Determine Nucleotide Sequence Cox1 Gene Sequence Chinook Salmon Embryo
This work was supported by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD, Basic Research Promotion Fund) (KRF-313-2007-2-F00076), and by the Natural Science and Engineering Research Council (NSERC) Discovery Grant to PTKW. The work of MSK was supported through funding to the Canadian Barcode of Life Network from Genome Canada, an NSERC Discovery Grant to D.H. Lynn and other sponsors (listed at http://www.BOLNET.ca).
- Chantangsi C, Lynn DH (2008) Phylogenetic relationships within the genus Tetrahymena inferred from the cytochrome c oxidase subunit 1 and the small subunit ribosomal RNA genes. Mol Phylogenet Evol 49: 979–987Google Scholar
- Dragesco A, Dragesco J, Coste F, Gasc C, Romestand B, Raymond J, Bouix G (1995) Philasterides dicentrarchi, n. sp. (Ciliophora, Scuticociliatida), a histophagous opportunistic parasite of Dicentarchus labrax (Linnaeus, 1758), a reared marine fish. Eur J Protistol 31:327–340Google Scholar
- Foissner W (1991) Basic light and scanning electron microscopic methods for taxonomic studies of ciliated protozoa. Eur J Protistol 27:313–330Google Scholar
- Goding JW (1993) Production of monoclonal antibodies. In: Goding JW (ed) Monoclonal antibodies: principles and practice. Academic, London, pp 175–176Google Scholar
- Lynn DH (2008) The ciliated protozoa. Characterization, classification, and guide to the literature. 3rd Ed. Springer, DordrechtGoogle Scholar
- Miao M, Song W, Clamp JC, Al-Rasheid KA, Al-Khedhairy AA, Al-Arifi S (2009) Further consideration of the phylogeny of some “traditional” heterotrichs (Protista, Ciliophora) of uncertain affinities, based on new sequences of the small subunit rRNA gene. J Eukaryot Microbiol 56:244–250PubMedCrossRefGoogle Scholar
- Song JY, Kitamura S-I, Oh MJ, Kang HS, Lee JH, Tanaka SJ, Jung SJ (2009a) Pathogenicity of Miamiensis avidus (syn. Philasterides dicentrarchi), Pseudocohnilembus persalinus, Pseudocohnilembus hargisi and Uronema marinum (Ciliophora, Scuticociliatida). Dis Aquat Org 83:133–143PubMedCrossRefGoogle Scholar
- Song W (2000) Morphological and taxonomical studies on some marine scuticociliates from China sea, with description of two new species, Philasterides armatalis sp. n. and Cyclidium varibonneti sp. n. (Protozoa: Ciliophora: Scuticociliatida). Acta Protozool 39:295–322Google Scholar
- Song W, Wilbert N (2000) Redefinition and redescription of some marine scuticociliates from China, with report of a new species, Metanophrys sinensis nov. spec. (Ciliophora, Scuticociliatida). Zool Anz 239:45–74Google Scholar
- Song W, Wilbert N (2002) Reinvestigations of three “well-known” marine scuticociliates: Uronemella filificum (Kahl, 1931) nov. gen., nov. comb., Pseudocohnilembus hargisi Evans & Thompson, 1964 and Cyclidium citrullus Cohn 1865, with description of the new genus Uronemella (Protozoa, Ciliophora, Scuticociliatida). Zool Anz 241:317–331CrossRefGoogle Scholar
- Thompson JC, Moewus L (1964) Miamiensis avidus n. g., n. sp., a marine facultative parasite in the ciliate order Hymenostomatida. J Protozool 11: 378–381Google Scholar