Lyrholm T, Gyllensten U
Department of Zoology, Stockholm University, Sweden.
Proc Biol Sci. 1998 Sep 7;265(1406):1679-84. doi: 10.1098/rspb.1998.0488.
The genetic variability and population structure of worldwide populations of the sperm whale was investigated by sequence analysis of the first 5'L 330 base pairs in the mitochondrial DNA (mtDNA) control region. The study included a total of 231 individuals from three major oceanic regions, the North Atlantic, the North Pacific and the Southern Hemisphere. Fifteen segregating nucleotide sites defined 16 mtDNA haplotypes (lineages). The most common mtDNA types were present in more than one oceanic region, whereas ocean-specific types were rare. Analyses of heterogeneity of mtDNA type frequencies between oceans indicated moderate (GST = 0.03) but statistically significant (p = 0.0007) genetic differentiation on a global scale. In addition, strong genetic differentiation was found between potential social groups (GST = 0.03-0.6), indicating matrilineal relatedness within groups. The global nucleotide diversity was quite low (pi = 0.004) implying a recent common mtDNA ancestry (< 100,000) years ago) and a young global population structure. However, within this time period, female dispersal has apparently been limited enough to allow the development of global mtDNA differentiation. The results are consistent with those from observational studies and whaling data indicating stable social affiliations, some degree of area fidelity and latitudinal range limitations in groups of females and juveniles.
通过对线粒体DNA（mtDNA）控制区首个5'L 330个碱基对进行序列分析，研究了全球抹香鲸种群的遗传变异性和种群结构。该研究共纳入了来自三个主要大洋区域（北大西洋、北太平洋和南半球）的231个个体。15个分离核苷酸位点定义了16种mtDNA单倍型（谱系）。最常见的mtDNA类型存在于多个大洋区域，而特定大洋的类型则很罕见。对不同大洋间mtDNA类型频率异质性的分析表明，在全球范围内存在中等程度（GST = 0.03）但具有统计学意义（p = 0.0007）的遗传分化。此外，在潜在的社会群体之间发现了强烈的遗传分化（GST = 0.03 - 0.6），表明群体内部存在母系亲缘关系。全球核苷酸多样性相当低（pi = 0.004），这意味着最近有一个共同的mtDNA祖先（< 100,000年前）以及一个年轻的全球种群结构。然而，在这个时间段内，雌性的扩散显然受到了足够的限制，从而导致了全球mtDNA分化的发展。这些结果与观察性研究和捕鲸数据的结果一致，表明雌性和幼鲸群体中存在稳定的社会关系、一定程度的区域忠诚度以及纬度范围限制。
