|Van Berkum, Peter|
Submitted to: Journal of Eukaryotic Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/9/1999
Publication Date: N/A
Interpretive Summary: There is increasing concern over the integrity and the biodiversity of the Atlantic Coast and the Chesapeake Bay habitats following the collapse of the eastern shore fisheries. Decline in the eastern shore oyster industry is attributed to infection of the protozoan, Perkensis marinus. Although these parasites have been identified in 60 different species of molluscs, little is known about their diversity and speciation, their pathogenicity, and their host specificity. Identification of the parasites traditionally has been based on morphology and biochemical phenotypes. From our study we conclude that softshell clams in the Chesapeake Bay may be infected by multiple genotypes of the oyster parasite, Perkensis. Also, we describe a molecular approach for the rapid identification of Perkensis. This information will be useful for scientists.
Technical Abstract: Sequence analysis and riboprinting of the small subunit ribosomal RNA genes were used to characterize two morphologically different Perkensis species isolated from the gill (G117) and the hemolymph (H49) of the softshell clam, Mya arenaria. Sequence data of the Polymerase Chain Reaction-amplified ribosomal RNA loci of G117 and H49 indicated that these genes are 1803 and 1806 base-pair long, respectively. A sequence similarity of 98.9% was calculated among ribosomal RNA sequences of the two isolates of this study and the published sequences of Perkesis marinus from the American eastern shore oyster, Crassostrea virginica, and Perkensis sp. from the blood cockle of the Australian mollusc, Anadara trapezia. From a phylogenetic tree obtained from Jukes-Cantor distances of the aligned ribosomal RNA gene sequences of 13 eukaryotic taxa using the Neighbor-Joining method, we showed that G117 and H49 clustered within the genus Perkensis. Guided by the sequence data of Perkensis marinus (accession #X75762) and Perkensis sp. (Access #L07375), restriction endonucleases were selected for restriction fragment analysis of the Polymerase Chain Reaction products of the small subunit ribosomal RNA genes (riboprinting). Riboprinting was used to distinguish the four members of the genus Perkensis from each other.