SSU rRNA gene sequence reveals two genotypes of Spironucleus barkhanus (Diplomonadida) from farmed and wild Arctic charr Salvelinus alpinus

Diseases of Aquatic Organisms

Anders Jørgensen¹  Erik Sterud¹ 

关键词: Spironucleus;    Salmonids;    SSU rDNA;   

DOI  :  10.3354/dao062093

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: Spironucleus barkhanus isolated from the blood of Arctic charr Salvelinus alpinus from a marine fish farm were genetically compared with S. barkhanus isolated from the gall bladder of wild Arctic charr. The wild Arctic charrwere caught in the lake used as the water source for the hatchery from which the farmed fish originated. Sequencing of the small subunit ribosomal RNAgene (SSU rDNA) from these 2 populations showed that the isolates obtained from farmed and wild Arcticcharr were only 92.7% similar. Based on the sequence differences between these isolates, it is concluded that the parasites isolated from the farmed fish have not been transmitted from wild Arctic charr in the hatchery’s fresh water source. It istherefore most likely that the farmed fish were infected by S. barkhanus after they were transferred to seawater. S. barkhanus isolated from diseased farmed Arctic charr were 99.7% similar to the isolates obtained from diseased farmedChinook (Canada) and Atlantic salmon (Norway). The high degree of sequence similarity between S. barkhanus from farmed Arctic charr, Chinook and Atlantic salmon indicates that systemic spironucleosis may be caused by specific strains/variants ofthis parasite. The genetic differences between the isolates of farmed and wild fish are of such magnitude that their conspecificity should be questioned.

【 授权许可】

Unknown