Hierarchical structure of mitochondrial DNA gene flow among humpback whales Megaptera novaeangliae, world‐wide

Abstract

The genetic structure of humpback whale populations and subpopulation divisions is described by restriction fragment length analysis of the mitochondrial (mt) DNA from samples of 230 whales collected by biopsy darting in 11 seasonal habitats representing six subpopulations, or 'stocks', world-wide. The hierarchical structure of mtDNA haplotype diversity among population subdivisions is described using the analysis of molecular variance (AMOVA) procedure, the analysis of gene identity, and the genealogical relationship of haplotypes as constructed by parsimony analysis and distance clustering. These analyses revealed: (i) significant partitioning of world-wide genetic variation among oceanic populations, among subpopulations or 'stocks' within oceanic populations and among seasonal habitats within stocks; (ii) fixed categorical segregation of haplotypes on the south-eastern Alaska and central California feeding grounds of the North Pacific; (iii) support for the division of the North Pacific population into a central stock which feeds in Alaska and winters in Hawaii, and an eastern or 'American' stock which feeds along the coast of California and winters near Mexico; (iv) evidence of genetic heterogeneity within the Gulf of Maine feeding grounds and among the sampled feeding and breeding grounds of the western North Atlantic; and (v) support for the historical division between the Group IV (Western Australia) and Group V (eastern Australia, New Zealand and Tonga) stocks in the Southern Oceans. Overall, our results demonstrate a striking degree of genetic structure both within and between oceanic populations of humpback whales, despite the nearly unlimited migratory potential of this species. We suggest that the humpback whale is a suitable demographic and genetic model for the management of less tractable species of baleen whales and for the general study of gene flow among long-lived, mobile vertebrates in the marine ecosystem.

Organismal and 'gametic' capture-recapture using microsatellite genotyping confirm low abundance and reproductive autonomy of humpback whales on the wintering grounds of New Caledonia

“…This is in contrast with the increase in numbers exhibited along the eastern coast of Australia (Group V) and Western Australia (Group IV) (e.g. Bryden et al 1990, Bannister 1994, Paterson et al 1994, Anonymous 2000.…”

Genetic population structure of minke whales Balaenoptera acutorostrata from Greenland, the North East Atlantic and the North Sea probably reflects different ecological regions

“…In a simulation study based on 2 large mammals (the blue whale Balaenoptera musculus, and the Asian elephant Elephas maximus), Tiedemann et al (2000) illustrated that at the nuclear DNA level an increase in female migration will influence the population structure significantly more than an 274 Baker et al (1994) detected a population structure in the maternally inherited mitochondrial DNA. Based on a RFLP study of the mtDNA, Baker et al (1994) demonstrated that humpback whales show strong fidelity to migration destinations such as feeding grounds. They explained this to be a result of a transmission of feeding and migration strategies from mother to calf.…”

“…The existence of genetically differentiated groups of whales at summer feeding grounds was indicated in studies of North Atlantic humpback whales Megaptera novaeanglia (Baker et al 1994, Palsbøll et al 1995.…”

Bucking the trend: genetic analysis reveals high diversity, large population size and low differentiation in a deep ocean cetacean

“…Genomic DNA was isolated from tissue using proteinase K digestion followed by a standard 25:24:1 Phenol:Chloroform:Isoamyl protocol as described by Sambrook et al (1989) and modified by Baker et al (1994), followed by ethanol precipitation. A 530 bp fragment of DNA from the mitochondrial control region was amplified and sequenced in both directions according to methods described in Thompson et al (2013) using the primer pair Dlp1.5 and Dlp8G.…”