Population genetic structure of North Atlantic, Mediterranean Sea and Sea of Cortez fin whales, Balaenoptera physalus (Linnaeus 1758): analysis of mitochondrial and nuclear loci
Source: Molecular Ecology, Volume 7, Number 5, May 1998 , pp. 585-599(15)
Abstract:Samples were collected from 407 fin whales, Balaenoptera physalus, at four North Atlantic and one Mediterranean Sea summer feeding area as well as the Sea of Cortez in the Pacific Ocean. For each sample, the sex, the sequence of the first 288 nucleotides of the mitochondrial (mt) control region and the genotype at six microsatellite loci were determined. A significant degree of divergence was detected at all nuclear and mt loci between North Atlantic/Mediterranean Sea and the Sea of Cortez. However, the divergence time estimated from the mt sequences was substantially lower than the time elapsed since the rise of the Panama Isthmus, suggesting occasional gene flow between the North Pacific and North Atlantic ocean after the separation of the two oceans. Within the North Atlantic and Mediterranean Sea, significant levels of heterogeneity were observed in the mtDNA between the Mediterranean Sea, the eastern (Spain) and the western (the Gulf of Maine and the Gulf of St Lawrence) North Atlantic. Samples collected off West Greenland and Iceland could not be unequivocally assigned to either of the two areas. The homogeneity tests performed using the nuclear data revealed significant levels of divergence only between the Mediterranean Sea and the Gulf of St Lawrence or West Greenland. In conclusion, our results suggest the existence of several recently diverged populations in the North Atlantic and Mediterranean Sea, possibly with some limited gene flow between adjacent populations, a population structure which is consistent with earlier population models proposed by Kellogg, Ingebrigtsen, and Sergeant.
Document Type: Research Article
Affiliations: 1: Institute of Zoology, Department of Population Biology, University of Copenhagen, DK-2100, Copenhagen, Denmark, , 2: Department of Animal Biology, Faculty of Biology, University of Barcelona, 08071 Barcelona, Spain, , 3: Allied Whale, College of the Atlantic, Bar Harbor, Maine, 04609 USA, , 4: Greenlandic Fisheries Research Institute, Nuuk, Greenland, , 5: Tethys Research Institute, Acquario Civico, 20121 Milano, Italy, , 6: Mingan Island Cetacean Study Inc., St-Lambert, Quebec, J4P 1T3 Canada, , 7: Program for Whale Research, Marine Research Institute, 121 Reykjavik, Iceland, , 8: Department of de Biologia Marina, Universidad Autonoma de Baja California Sur, La Paz, 23080 B.C.S., Mexico, ,
Publication date: May 1, 1998