A repetitive element in the genome of Atlantic salmon, Salmo salar.

ABSTRACT

When Atlantic salmon (Salmo salar) genomic DNA is digested with the restriction endonuclease BglI and the fragments separated by agarose-gel electrophoresis, bands corresponding to approximately 430 and 923 bp are visualized after EtdBr staining. The 923-bp band was excised from a preparative gel and used to screen a salmon genomic library for recombinant phage (re-phage) containing the repeat. The BglI repeat element is tandemly arrayed, and an array from one re-phage has been sequenced. The BglI repeats comprise 2.3% of the S. salar genome and have been found in the vicinity of rDNA genes (encoding ribosomal RNA). Southern blot hybridization detects a homologue of the Atlantic salmon BglI repeat in the brown trout (Salmo trutta) genome, but not in other salmonids. However, a DNA fragment with sequence homology to part of the BglI repeat has recently been isolated from Arctic charr (Salvelinus alpinus; S.E. Hartley and W.S.D., unpublished data). In addition, the BglI repeat detects RFLPs in Atlantic salmon.