Publication Abstract

Patterns of occurrence and 18S rDNA sequence variation of PKX (Tetracapsula bryosalmonae), the causative agent of salmonid proliferative kidney disease.

Patterns of occurrence and 18S rDNA sequence variation of PKX (Tetracapsula bryosalmonae), the causative agent of salmonid proliferative kidney disease

B. Okamura, C.L. Anderson, M. Longshaw, S.W.Feist, E.U.Canning.

Recent progress in understanding the nature and source of Proliferative Kidney Disease includes identification of freshwater bryozoans as natural hosts of the myxozoan parasite that causes the disease in salmonid fish and formal description of the parasite as Tetracapsula bryosalmonae. This paper presents data on patterns of occurrence of T. bryosalmonae and sequence variation amongst isolates. T. bryosalmonae has been found to infect bryozoans that range from primitive to advanced genera within the Class Phylactolaemata and that differ in growth form and habits. Infected bryozoans have been collected in diverse habitats including cold, clear streams and warm, eutrophic lakes. Temporal surveys suggest a short season of infection in bryozoans, and reveal annual variations in infection levels. Spatial variation in incidence of infection is implied by the apparent absence of T. bryosalmonae in many bryozoan populations. The significance of minor variation in partial sequences of 18S rDNA requires further investigation, particularly with regard to whether all variants are capable of inducing PKD in salmonids. The information presented here provides the first significant insights into the ecology of T. bryosalmonae.

Reference:

B. Okamura, C.L. Anderson, M. Longshaw, S.W.Feist, E.U.Canning, 2001. Patterns of occurrence and 18S rDNA sequence variation of PKX (Tetracapsula bryosalmonae), the causative agent of salmonid proliferative kidney disease. Journal of Parasitology, 87(2): 379-385

B. Okamura, C.L. Anderson, M. Longshaw*, S.W. Feist* and E.U.Canning

Journal of Parasitology, 87(2): 379-385