Analysis of the contemporary geographic distributions of mtDNA haplotypic diversity of sockeye salmon (Oncorhynchus nerka Walbaum) on the Asian part of its range and consideration of possible scenarios for microevolution of the species were performed. In total, 172 specimens of sockeye salmon from different rivers of Kamchatka, Chukotka, north coast of the Sea of Okhotsk, and from the Kuril Islands were analyzed using the entire mtDNA control region (1,010 bp) sequencing. After multiple alignments of the sequences 16 polymorphic sites were identified. Most of substitutions were detected in the first and the last thirds of the D‐loop sequence, as well as one insertion was registered in the poly‐T region. Two mass haplotypes (Hap_1_10T and Hap_2_13T) were revealed; they were present in most samples and differed by three substitutions and two indels. All the sequence variants were distributed among two haplogroups in compliance with the mass haplotypes. The star‐shaped topology of the MST‐tree points to a rapid increase in the diversity of groups, indicating a rapid expansion of the species after its number reducing in the past. The diversity of the first haplogroup was higher, but its main fraction fell on the samples from the middle reach of Kamchatka River, which seems to be a refugium during the Late Pleistocene glaciation. Presence of both haplogroups in most populations in approximately equal proportions indicates that the entire Asian part of the sockeye salmon range is a zone of secondary contact. We hypothesize that Hap_2_13T had more ancient origin and the Hap_1_10T was formed somewhat later, apparently in Asia, because almost all transitional forms between the haplogroups were found in Iturup Island populations.

中文翻译：

---

基于线粒体DNA控制区多态性分析的亚洲红鲑（Oncorhynchus nerka）系统记录

大马哈鱼mtDNA单倍型多样性的当代地理分布分析（Oncorhynchus nerka）Walbaum）在其亚洲范围内进行了研究，并考虑了该物种微观进化的可能情况。使用整个mtDNA控制区域（1,010 bp）测序，总共分析了172个来自堪察加半岛，楚科奇半岛，鄂霍次克海北海岸不同河流以及千岛群岛的红鲑鱼标本。在序列的多次比对之后，鉴定了16个多态性位点。在D-loop序列的前三分之一和后三分之一中检测到大多数取代，并且在poly-T区记录了一个插入。揭示了两个质量单倍型（Hap_1_10T和Hap_2_13T）。它们存在于大多数样品中，并且相差三个取代和两个插入缺失。所有序列变体均按照整体单倍型分布在两个单倍群中。MST树的星形拓扑结构表明，群体多样性迅速增加，表明过去物种数量减少后物种迅速扩张。第一个单倍群的多样性较高，但主要部分落在堪察加河中游的样本上，这似乎是晚更新世冰川期的避难所。大多数种群中两个单倍群的存在比例大致相等，这表明红鲑鱼范围的整个亚洲部分是次级接触区。我们假设Hap_2_13T具有更古老的起源，而Hap_1_10T的形成则稍晚一些，显然是在亚洲，因为单倍群之间几乎所有的过渡形式都在伊图鲁普岛人口中发现。