CHARACTERIZATION OF A REPETITIVE ELEMENT DETECTED BY NHEI IN THE GENOMES OF SALMO SPECIES

The genomes of the two species in the genus Salmo (Atlantic salmon, S. salar; brown trout, S. trutta) contain a 380-bp repetitive element that is flanked by the recognition sequence of the restriction enzyme NheI. These elements, which comprise approximately 1.2% of the salmon genome, do not exist in long tandem arrays as is typical of satellite DNA. A comparison of the sequences of 16 salmon and 7 trout elements revealed that members of this family of repetitive DNA are closely related to one another (over 95% identity). Subfamily structure exists and there is evidence that members of the same subfamilies are found in both Salmo species. A search of the GenBank database indicated that sequences homologous to the NheI repeat are located within a 1424-bp segment inserted immediately downstream of the 5' end of a Tc1 transposon-like sequence isolated from Atlantic salmon