Characterization of the heterochromatin in moose (Alces alces) chromosomes.

The karyotype of moose (2n = 68) is characterized by very large C-bands close to the centromeres of most chromosomes. The C-banded material represents 40% of the genome. For further characterization of the heterochromatin chromosome spreads were treated with restriction endonucleases and the restriction enzyme (Re) banding pattern was analyzed. HaeIII, AluI, MboI, RsaI and HinfI produced informative Re-bands. DdeI induced an even digestion with no banding. Staining with chromomycin A3 produced bright fluorescence in regions corresponding to C-bands. Labeling with BrdUrd during late S phase differentiates four regions in the C banded area. The sequence of these regions from centromere to telomere are: late, early, late and early replicating. The authors propose the existence of five satellite DNA families with distinctive characteristics of G-C and A-Trichness and different replication timing, and point out the different clusters for the endonucleases detailed above and their varying location in the chromosomes examined.