Hoelzel A R, Dahlheim M, Stern S J
National Cancer Institute, Laboratory of Viral Carcinogenesis, Frederick, Maryland, USA.
J Hered. 1998 Mar-Apr;89(2):121-8. doi: 10.1093/jhered/89.2.121.
Killer whales from the coastal waters off California through Alaska were compared for genetic variation at three nuclear DNA markers and sequenced for a total of 520 bp from the mitochondrial control region. Two putative sympatric populations that range throughout this region were compared. They can be distinguished by social and foraging behavior and are known as "residents" and "transients". We found low levels of variation within populations compared to other cetacean species. Comparisons between fish (resident) versus marine mammal (transient) foraging specialists indicated highly significant genetic differentiation at both nuclear and mitochondrial loci. This differentiation is at a level consistent with intraspecific variation. A comparison between two parapatric resident populations showed a small but fixed mtDNA haplotype difference. Together these data suggest low levels of genetic dispersal between foraging specialists and a pattern of genetic differentiation consistent with matrifocal population structure and small effective population size.
对来自加利福尼亚沿海水域至阿拉斯加的虎鲸进行了比较，分析了三个核DNA标记的遗传变异，并对线粒体控制区总共520个碱基对进行了测序。比较了在该区域分布的两个假定同域分布种群。它们可通过社会行为和觅食行为加以区分，分别被称为“定居型”和“瞬变型”。与其他鲸类物种相比，我们发现种群内部的变异水平较低。对以鱼类为食（定居型）和以海洋哺乳动物为食（瞬变型）的觅食专家进行比较，结果表明在核基因座和线粒体基因座上均存在高度显著的遗传分化。这种分化程度与种内变异一致。对两个邻域分布的定居种群进行比较，结果显示线粒体DNA单倍型存在微小但固定的差异。这些数据共同表明，觅食专家之间的基因扩散水平较低，并且遗传分化模式与母系群体结构和较小的有效种群规模一致。
