Larsen A H, Sigurjónsson J, Oien N, Vikingsson G, Palsbøll P
Department of Population Biology, University of Copenhagen, Denmark.
Proc Biol Sci. 1996 Nov 22;263(1376):1611-8. doi: 10.1098/rspb.1996.0236.
It has been speculated that humpback whales, Megaptera novaeangliae, from the northeastern North Atlantic breed in tropical waters off the coast of West Africa and therefore that they represent a separate breeding population from that which winters in the West Indies. We determined the genotype at six microsatellite loci as well as the sequence of the first 288 nucleotides in the mitochondrial control region of 133 skin biopsies collected from humpback whales in the central North Atlantic (Iceland and Jan Mayen) and the northeastern North Atlantic (Bear Island and the northern coast of Norway). We detected no significant deviations from Hardy-Weinberg proportions nor any differences in genotype frequencies between localities at the nuclear loci. However, the mitochondrial analyses revealed two distinct matrilineal aggregations: the central and the northeastern North Atlantic. Our findings were not compatible with the idea of a separate eastern North Atlantic breeding ground unless one has been established recently. The proposed alternative hypothesis of a common North Atlantic panmictic population (wintering primarily in the West Indies) in which individual whales display maternally directed site-fidelity to specific feeding grounds was supported by re-sightings of two northeastern North Atlantic humpback whales in the West Indies.
据推测，北大西洋东北部的座头鲸（Megaptera novaeangliae）在西非海岸的热带水域繁殖，因此它们与在西印度群岛越冬的座头鲸属于不同的繁殖群体。我们测定了从北大西洋中部（冰岛和扬马延岛）以及北大西洋东北部（熊岛和挪威北部海岸）的座头鲸身上采集的133份皮肤活检样本在6个微卫星位点的基因型，以及线粒体控制区前288个核苷酸的序列。我们未检测到与哈迪-温伯格平衡比例的显著偏差，在核基因座上也未发现不同地点之间基因型频率存在差异。然而，线粒体分析揭示了两个不同的母系群体：北大西洋中部群体和东北部群体。我们的研究结果与北大西洋东部存在一个独立繁殖地的观点不一致，除非这个繁殖地是最近才形成的。两只在北大西洋东北部的座头鲸在西印度群岛被重新发现，这支持了另一种假设，即存在一个北大西洋泛交群体（主要在西印度群岛越冬），其中个体鲸鱼对特定觅食地表现出母系定向的地点忠实性。
