Heterochromatin distribution and structure in Gymnothorax unicolor (Anguilliformes, Muraenidae)

Mitotic chromosomes of the moray eel, Gymnothorax unicolor, were digested in situ with AluI, HaeIII, MboI and DdeI restriction endonucleases, and the results were compared with those obtained in the other Mediterranean species of the same family, Muraena helena. Thanks to restriction endonuclease- (RE-) banding technique, it is possible to study the distribution and structure of heterochromatic regions, since subsets of constitutive heterochromatin sensitive/resistant to nuclease action can be observed. From an analysis of the banding patterns it was possible to study the karyotypic structural changes between the two species