Shedko S V, Miroshnichenko I L, Nemkova G A, Koshelev V N, Shedko M B
Genetika. 2015 Feb;51(2):200-16.
The variability of the mtDNA control region (D-loop) was examined in Amur sturgeon endemic to the Amur River. This species is also classified as critically endangered by the IUCN Red List of Threatened species. Sequencing of 796- to 812-bp fragments of the D-loop in 112 sturgeon collected in the Lower Amur revealed 73 different genotypes. The sample was characterized by a high level of haplotypic (0.976) and nucleotide (0.0194) diversity. The identified haplotypes split into two well-defined monophyletic groups, BG (n = 39) and SM (n = 34), differing (HKY distance) on average by 3.41% of nucleotide positions upon an average level of intragroup differences of 0.54 and 1.23%, respectively. Moreover, the haplotypes of the SM groups differed by the presence of a 13-14 bp deletion. Most ofthe samples (66 out of 112) carried BG haplotypes. Overall, the pattern of pairwise nucleotide differences and the results of neutrality tests, as well as the results of tests for compliance with the model of sudden demographic expansion or with the model of exponential growth pointed to a past significant increase in the number of Amur sturgeon, which was most clearly manifested in the analysis of data on the BG haplogroup. The constructed Bayesian skyline plots showed that this growth began about 18 to 16 thousand years ago. At present, the effective size of the strongly reduced (due to overharvesting) population of Amur sturgeon may be equal to or even lower than it was before the beginning of this growth during the Last Glacial Maximum. The presence in the mitochondrial gene pool ofAmur sturgeon of two haplogroups, their unequal evolutionary dynamics, and, judging by scanty data, their unequal representation in the Russian and Chinese parts of the Amur River basin point to the possible existence of at least two distinct populations of Amur sturgeon in the past.
对黑龙江流域特有的黑龙江鲟线粒体DNA控制区（D-loop）的变异性进行了研究。该物种在世界自然保护联盟濒危物种红色名录中也被列为极度濒危物种。对在黑龙江下游采集的112条鲟鱼的D-loop中796至812碱基对片段进行测序，发现了73种不同的基因型。该样本具有高水平的单倍型多样性（0.976）和核苷酸多样性（0.0194）。所鉴定的单倍型分为两个明确的单系类群，BG（n = 39）和SM（n = 34），平均核苷酸位置差异（HKY距离）分别为3.41%，而组内平均差异水平分别为0.54%和1.23%。此外，SM类群的单倍型因存在13 - 14碱基对的缺失而有所不同。大多数样本（112个中的66个）携带BG单倍型。总体而言，成对核苷酸差异模式、中性检验结果以及符合突然种群扩张模型或指数增长模型的检验结果表明，过去黑龙江鲟数量有显著增加，这在BG单倍群数据分析中最为明显。构建的贝叶斯天际线图显示，这种增长始于约1.8万至1.6万年前。目前，由于过度捕捞，数量大幅减少的黑龙江鲟种群的有效规模可能等于甚至低于末次盛冰期这种增长开始之前的规模。黑龙江鲟线粒体基因库中存在两个单倍群，它们不同的进化动态，以及从稀少数据判断它们在黑龙江流域俄罗斯和中国部分地区的不同代表性，表明过去可能至少存在两个不同的黑龙江鲟种群。
