PATTERNS OF GENETIC-VARIABILITY AT INDIVIDUAL MINISATELLITE LOCI IN MINKE WHALE BALAENOPTERA-ACUTOROSTRATA POPULATIONS FROM 3 DIFFERENT OCEANS

The genetic variability at six cloned minisatellite loci was analyzed in minke whale populations from the North Atlantic, North Pacific, and Antarctic Oceans. Three loci displayed only a few different alleles i n each of the three populations, with heterozygosity ranging from 0.00 to 0.47, and three loci revealed many different alleles in at least t wo of the three populations, with heterozygosity ranging up to 0.98. U sing small sample sizes, samples from two adjacent Antarctic Managemen t Areas were not found to differ significantly in allele frequencies a t any of the six loci. The use of principal coordinate analysis to det ect multilocus disequilibria was explored. No significant evidence was found of intrapopulation heterogeneity within the pooled Antarctic sa mple. Pronounced interoceanic differences were observed at every locus , confirming the existence of genetic isolation found earlier using mo re conventional marker systems. The populations from the three oceans appear to have diverged to such a degree that the hypervariable loci h ave had time to evolve independently and arrive at different evolution ary stages in different populations. The frequency of undetected ''nul l'' alleles is remarkably high in minke whale populations compared to human populations and is probably a result of the cloning protocol use d. Minisatellite loci are shown to provide a powerful population genet ic tool, supplying levels of resolution appropriate to different degre es of evolutionary divergence.