Circumpolar diversity and geographic differentiation of mtDNA in the critically endangered Antarctic blue whale (Balaenoptera musculus intermedia)

The Antarctic blue whale (Balaenoptera musculus intermedia) was hunted to near extinction between 1904 and 1972, declining from an estimated initial abundance of more than 250,000 to fewer than 400. Here, we describe mtDNA control region diversity and geographic differentiation in the surviving population of the Antarctic blue whale, using 218 biopsy samples collected under the auspices of the International Whaling Commission (IWC) during research cruises from 1990–2009. Microsatellite genotypes and mtDNA sequences identified 166 individuals among the 218 samples and documented movement of a small number of individuals, including a female that traveled at least 6,650 km or 131° longitude over four years. mtDNA sequences from the 166 individuals were aligned with published sequences from 17 additional individuals, resolving 52 unique haplotypes from a consensus length of 410 bp. From this minimum census, a rarefaction analysis predicted that only 72 haplotypes (95% CL, 64, 86) have survi...

南极蓝鲸（Balaenoptera musculus intermedia）在1904年至1972年间因过度捕捞濒临灭绝，其初始种群估计丰度超过25万头，最终锐减至不足400头。本研究依托国际捕鲸委员会（International Whaling Commission, IWC）1990年至2009年科考巡航期间采集的218份活检样本，对现存南极蓝鲸种群的线粒体DNA（mtDNA）控制区多样性与地理分化特征展开了描述。通过微卫星基因型（microsatellite genotypes）与mtDNA序列分析，研究团队在218份样本中鉴定出166头个体，并记录到少量个体的长距离移动事件，其中一头雌性蓝鲸在四年间至少移动了6650公里，或跨越131个经度。研究人员将这166头个体的mtDNA序列与已发表的17份额外个体序列进行比对，在410个碱基对（bp）的共识序列长度下，共解析出52个独特单倍型（haplotype）。基于此最小种群普查数据，稀化分析（rarefaction analysis）预测现存单倍型仅为72种（95%置信区间：64、86）……