Abyzova Galina Anatolievna, Nikitin Mikhail Aleksandrovich, Popova Olga Vladimirovna, Pasternak Anna Fedorovna
Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia.
Belozersky Institute for Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.
PeerJ. 2018 Nov 6;6:e5709. doi: 10.7717/peerj.5709. eCollection 2018.
Pelagic pteropods are widespread and can play an important role in the food webs and in biosedimentation in Arctic and Subarctic ecosystems. Previous publications have shown differences in the genetic structure of populations of from populations found in the Pacific Ocean and Svalbard area. Currently, there are no data on the genetic structure of populations in the seas of the Siberian Arctic. We assessed the genetic structure of from the Kara Sea populations and compared them with samples from around Svalbard and the North Pacific.
We examined genetic differences in from three different locations in the Kara Sea via analysis of a fragment of the mitochondrial gene COI. We also compared a subset of samples with from previous studies to find connections between populations from the Atlantic and Pacific Oceans.
65 individual from the Kara Sea were sequenced to produce 19 different haplotypes. This is comparable with numbers of haplotypes found in Svalbard and Pacific samples (24 and 25, respectively). Haplotypes from different locations sampled around the Arctic and Subarctic were combined into two different groups: H1 and H2. The H2 includes sequences from the Kara Sea and Svalbard, was present only in the Atlantic sector of the Arctic. The other genetic group, H1, is widespread and found throughout all populations. ϕ ST analyses also indicated significant genetic difference between the Atlantic and Pacific regions, but no differences between Svalbard and the Kara Sea.
The obtained results support our hypothesis about genetic similarity of populations from the Kara Sea and Svalbard: the majority of haplotypes belongs to the haplotype group H2, with the H1 group representing a minority of the haplotypes present. In contrast, in the Canadian Arctic and the Pacific Ocean only haplogroup H1 is found. The negative values of Fu's Fs indicate directed selection or expansion of the population. The reason for this pattern could be an isolation of the population during the Pleistocene glaciation and a subsequent rapid expansion of this species after the last glacial maximum.
远洋翼足类动物分布广泛，在北极和亚北极生态系统的食物网及生物沉积过程中发挥着重要作用。此前的研究表明，太平洋和斯瓦尔巴德地区的翼足类动物种群在遗传结构上存在差异。目前，尚无关于西伯利亚北极海域翼足类动物种群遗传结构的数据。我们评估了喀拉海种群的翼足类动物的遗传结构，并将其与来自斯瓦尔巴德群岛周边及北太平洋的样本进行了比较。
我们通过分析线粒体基因COI的一个片段，研究了喀拉海三个不同地点的翼足类动物的遗传差异。我们还将一部分样本与之前研究中的样本进行比较，以寻找大西洋和太平洋种群之间的联系。
对来自喀拉海的65只个体翼足类动物进行测序，得到了19种不同的单倍型。这与在斯瓦尔巴德群岛和太平洋样本中发现的单倍型数量相当（分别为24种和25种）。来自北极和亚北极地区不同采样地点的单倍型被归为两个不同的组：H1和H2。H2组包括来自喀拉海和斯瓦尔巴德群岛的序列，仅存在于北极的大西洋区域。另一个遗传组H1分布广泛，在所有翼足类动物种群中都有发现。ϕ ST分析还表明，大西洋和太平洋区域之间存在显著的遗传差异，但斯瓦尔巴德群岛和喀拉海之间没有差异。
所得结果支持了我们关于喀拉海和斯瓦尔巴德群岛翼足类动物种群遗传相似性的假设：大多数单倍型属于单倍型组H2，而H1组仅占所出现单倍型的少数。相比之下，在加拿大北极地区和太平洋仅发现单倍群H1。Fu's Fs的负值表明种群存在定向选择或扩张。这种模式的原因可能是更新世冰川期期间翼足类动物种群的隔离，以及末次盛冰期后该物种随后的快速扩张。
