Mikrocytos roughleyi taxonomic affiliation leads to the genus Bonamia (Haplosporidia)

Type Article
Date 2003-04
Language English
Author(s) Cochennec NathalieORCID1, Reece K.2, Berthe Franck1, Hine Mike3
Affiliation(s) 1 : IFREMER, Lab Genet & Pathol, F-17390 La Tremblade, France.
2 : Virginia Inst Marine Sci, Aquaculture Genet & Breeding Technol Ctr, Gloucester Point, VA 23062 USA.
3 : MAF Operat, Natl Ctr Dis Invest, Aquat Anim Dis, Wellington 6007, New Zealand.
Source Diseases of aquatic organisms (0177-5103) (Inter-Research), 2003-04 , Vol. 54 , N. 3 , P. 209-217
DOI 10.3354/dao054209
WOS© Times Cited 54
Keyword(s) Small subunit rDNA, Taxonomy, Microcell, Bonamosis, Saccostrea glomerata, Mikrocytos roughleyi
Abstract Microcell-type parasites of oysters are associated with a complex of diseases in different oyster species around the world. The etiological agents are protists of very small size that are very difficult to characterize taxonomically. Associated lesions may vary according to the host species, and their occurrence may be related to variations in tissue structure. Lesion morphology cannot be used to distinguish the different agents involved. Ultrastructural observations on Mikrocytos roughleyi revealed similarities with Bonamia spp., particularly in regard to the presence of electron-dense haplosporosomes and mitochondria, whose absence from M mackini also indicate that M roughleyi and M mackini are not congeneric. A partial small subunit (ssu) rRNA gene sequence of M roughleyi was determined. This partial sequence, 951 nucleotides in length, has 95.2 and 98.4% sequence similarities with B. ostreae and B. exitiosus ssu rDNA sequences, respectively. Polymorphisms among the ssu rDNA sequences of B. ostreae, B. exitiosus and M roughleyi allowed identification of restriction enzyme digestion patterns diagnostic for each species. Phylogenetic analysis based on the ssu rDNA data suggested that M roughleyi belongs in the phylum Haplosporidia and that it is closely related to Bonamia spp. On the basis of ultrastructural and molecular considerations, M roughleyi should be considered a putative member of the genus Bonamia.
Full Text
File Pages Size Access
publication-2816.pdf 9 1 MB Open access
Top of the page