Analysis of mitochondrial DNA diversity within and between North and SouthAtlantic right whales

DNA sequences of the mitochondrial control region of 180 North Atlantic rig ht whales (Eubalaena glacialis) and 16 South Atlantic right whales (E. aust ralis) have been determined using a combination of direct DNA sequencing an d single stranded conformation polymorphism (SSCP) analysis. Five haplotype s were found in E, glacialis, and 10 in E, australis, but none were shared, supporting the reproductive isolation and separate species status of the N orth and South Atlantic right whales. One haplotype in E, glacialis was fou nd in only three males born before 1982 and this matriline will likely be l ost soon. The nucleotide diversity estimates for the five North Atlantic ri ght whale haplotypes was 0.6% and 2.0% for the 10 haplotypes found in the S outh Atlantic right whales. The average haplotypic diversity was 0.87 in E. glacialis and 0.96 in E. australis, which is consistent with other studies showing a lower level of genetic variation in the North Atlantic right wha le. Phylogenetic analysis identified two major assemblages of haplotypes in E. australis from the samples collected from Peninsula Valdes, suggesting a mixing of two historically divergent populations. Using genetic distance measurements with a divergence tate of 0.5%-1.0%/myr, we estimate E, glacia lis diverged from E, australis 3-12.5 mya.