The importance of ice ages in diversification of Arctic collared lemmings (Dicrostonyx):: evidence from the mitochondrial cytochrome b region
The importance of ice ages in diversification of Arctic collared lemmings (Dicrostonyx):: evidence from the mitochondrial cytochrome b region
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DOI：
10.1111/j.1601-5223.1999.00301.x
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发表时间：
1999-01-01
期刊：
影响因子：
2.7
通讯作者：
Goropashnaya, AV
中科院分区：
文献类型：
--
作者：
Fedorov, VB;Goropashnaya, AV
对分布于环极地范围内的24只环冠狐猴线粒体细胞色素b区(804bp)的核苷酸序列变异进行了研究。MtDNA系统发育支持基于核型和杂交实验提出的四个种的划分，即欧亚大陆的D·torquatus和北美的D·groenlandicus、D·hudsonius和D·richardsoni。种间差异估计(平均4.89%)表明，辐射发生在更新世，支持了冰期-间冰期产生的替代事件对染色体可变的Dmicrostonx物种形成的重要性。北美物种群的单系性表明白令大陆桥发生了一次扩散事件，不支持形态上原始的哈德逊氏丝虫是欧亚大陆早期入侵的残留物，而格陵兰丝虫代表较晚的扩散事件的假说。在麦肯齐河上分歧有限(0.63%)的两个系统地理类群中，北美罗兰岛石斑鱼的划分与该物种在上一次冰期期间在位于劳伦蒂冰盖西北的一个以上避难区的分离是一致的。在欧亚Dolquatus中，Kolyma河以东地区的单倍型群具有基本位置。这支持了亚洲Beringia作为冻土带专家D.torquatus在晚更新世暖间冰期之一的避难地的重要性。
Variation in the nucleotide sequence of the mitochondrial cytochrome b region (804 bp) was examined for 24 individuals of collared lemmings Dicrostonyx sampled over the circumpolar distribution range of this genus. The mtDNA phylogeny supports the division of Dicrostonyx into four species suggested on the basis of karyotypes and hybridisation experiments, the Eurasian D. torquatus and the North American D. groenlandicus, D. hudsonius and D. richardsoni. The interspecific divergence estimates (mean 4.89 %) suggest that radiation took place during the Pleistocene and gives support for the importance of vicariant events generated by the glacial-interglacial periods for speciation in the chromosomally variable Dicrostonyx. The monophyly of the North America species group indicates one dispersion event across the Bering Land Bridge and does not support the hypothesis that the morphologically primitive D. hudsonius is a relict of an earlier invasion from Eurasia while D. groenlandicus represents a later dispersion event. The division of the North America D. groenlandicus in the two phylogeographic groups with limited divergence (0.63 %) across the Mackenzie river is consistent with separation of this species in more than one refugial area located to the north west of the Laurentide ice sheet during the last glaciation. Within the Eurasian D. tolquatus, the group of haplolypes from the area to the east of the Kolyma river has the basal position. This gives support for the importance of the Asian Beringia as a refugial area for the tundra specialist, D. torquatus, during one of the warm interglacials in the late Pleistocene.