Data from: 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 survived in the contemporary population of Antarctic blue whales. However, haplotype diversity was relatively high (0.968±0.004), perhaps as a result of the longevity of blue whales and the relatively recent timing of the bottleneck. Despite the potential for circumpolar dispersal, we found significant differentiation in mtDNA diversity (FST = 0.032, p<0.005) and microsatellite alleles (FST = 0.005, p<0.05) among the six Antarctic Areas historically used by the IWC for management of blue whales.南极蓝鲸（Antarctic blue whale，Balaenoptera musculus intermedia）在1904年至1972年间遭受过度捕猎，几近灭绝，种群规模从最初估算的25万余头锐减至不足400头。本研究依托1990至2009年间由国际捕鲸委员会（International Whaling Commission, IWC）统筹组织的科考航次所采集的218份皮肤活检样本，对现存南极蓝鲸种群的线粒体DNA（mitochondrial DNA, mtDNA）控制区多样性及地理分化特征展开描述。通过微卫星（microsatellite）基因型分析与线粒体DNA序列鉴定，218份样本中共甄别出166头独特个体，并记录到少量个体的长距离移动案例，其中一头雌性蓝鲸在四年时间内至少迁徙了6650公里，或跨越131个经度。将166头个体的线粒体DNA序列与已公开的17份同源序列进行比对，在410碱基对（base pair, bp）的共识序列长度范围内，共解析出52个独特单倍型（haplotype）。基于该最小种群普查结果，稀疏分析（rarefaction analysis）预测当代南极蓝鲸种群仅留存72个单倍型（95% CL, 64, 86）。不过，当前种群的单倍型多样性仍相对较高（0.968±0.004），这或许源于蓝鲸的长寿命特性以及种群瓶颈事件发生的时间相对较近。尽管南极蓝鲸存在环极扩散的潜在可能性，但本研究仍发现，在国际捕鲸委员会历史上用于蓝鲸管理的六个南极管理区域之间，线粒体DNA多样性（FST=0.032，p<0.005）与微卫星等位基因（microsatellite alleles）均存在显著的遗传分化（FST=0.005，p<0.05）。