RESTRICTION ENZYME BANDING IN ATLANTIC SALMON (SALMO-SALAR) AND BROWN TROUT (SALMO-TRUTTA)

Fixed metaphase chromosomes of brown trout and Atlantic salmon were digested with various restriction enzymes and stained with Giemsa. C band-like patterns were produced in both species by Alu I, Dde I, Hae III and Mbo I. Alu I revealed extra chromosome bands in brown trout which allowed identification of additional chromosome pairs, while the other three enzymes produced patterns identical to C banding. In the Atlantic salmon Dde I revealed telomeric bands at all telomeres in addition to the conventional C bands and all four enzymes had differential effects on the nucleolar organizer-associated heterochromatin. The relevance of these findings to chromosome identification and constitutive heterochromatin organization in salmonid fishes is discussed.