FN Archimer Export Format PT J TI Molecular detection of the oyster parasite Mikrocytos mackini, and a preliminary phylogenetic analysis BT AF CARNEGIE, Ryan MEYER, Gary BLACKBOURN, Janice COCHENNEC, Nathalie BERTHE, Franck BOWER, Susan AS 1:1;2:1;3:1;4:2;5:2;6:1; FF 1:;2:;3:;4:PDG-DRV-RA-DCOP-AT;5:PDG-DRV-RA-LGP;6:; C1 Fisheries & Oceans Canada, Pacific Biol Stn, Sci Branch, Nanaimo, BC V9T 6N7, Canada. IFREMER, Lab Genet Aquaculture & Pathol, F-17390 La Tremblade, France. C2 MPO, CANADA IFREMER, FRANCE SI TAHITI LA TREMBLADE SE PDG-DRV-RA-DCOP-AT PDG-DRV-RA-LGP IN WOS Ifremer jusqu'en 2018 copubli-int-hors-europe IF 1.263 TC 61 UR https://archimer.ifremer.fr/doc/2003/publication-2814.pdf LA English DT Article DE ;Fluorescent in situ hybridization;PCR validation;Mikrocytos mackini;Denman Island disease AB The protistan parasite Mikrocytos mackini, the causative agent of Denman Island disease in the oyster Crassostrea gigas in British Columbia, Canada, is of wide concern because it can infect other oyster species and because its life cycle, mode of transmission, and origins are unknown. PCR and fluorescent in situ hybridization (FISH) assays were developed for M mackini, the PCR assay was validated against standard histopathological diagnosis, and a preliminary phylogenetic analysis of the M mackini small-subunit ribosomal RNA gene (SSU rDNA) was undertaken. A PCR designed specifically not to amplify host DNA generated a 544 bp SSU rDNA fragment from M mackini-infected oysters and enriched M. mackini cell isolates, but not from uninfected control oysters. This fragment was confirmed by FISH to be M mackini SSU rDNA. A M mackini-specific PCR was then designed which detected 3 to 4x more M mackini infections in 1056 wild oysters from Denman Island, British Columbia, than standard histopathology. Mikrocytos mackini prevalence estimates based on both PCR and histopathology increased (PCR from 4.4 to 7.4%, histopathology from 1.2 to 2.1%) when gross lesions were processed in addition to standard samples (i.e. transverse sections for histopathology, left outer palp DNA for PCR). The use of histopathology and tissue imprints plus PCR, and standard samples plus observed gross lesions, represented a 'total evidence' approach that provided the most realistic estimates of the true prevalence of M mackini. Maximum parsimony and evolutionary distance phylogenetic analyses suggested that M mackini may be a basal eukaryote, although it is not closely related to other known protistan taxa. PY 2003 PD APR SO Diseases of aquatic organisms SN 0177-5103 PU Inter-Research VL 54 IS 3 UT 000184149700006 BP 219 EP 227 DI 10.3354/dao054219 ID 2814 ER EF