Wildlife Institute of India, 248001, Dehradun, Uttarakhand, India.
Zoological Survey of India, 700020, Kolkata, India.
Mol Biol Rep. 2022 Nov;49(11):11177-11186. doi: 10.1007/s11033-022-07832-0. Epub 2022 Sep 12.
Populations exhibit signatures of local adaptive traits due to spatial and environmental heterogeneity resulting in microevolution. The blue sheep is widely distributed across the high Asian mountains and are the snow leopard's principal prey species. These mountains differ in their evolutionary history due to differential glaciation and deglaciation periods, orography, and rainfall patterns, and such factors causes diversification in species.
Therefore, we assess the phylogeographic status of blue sheep using the mitochondrial cytochrome b gene (220 bp) across the Indian Himalayan region (IHR) and its relationship with other populations. Of the observed five haplotypes, two and three were from the western Himalayas (WH) and eastern Himalayas (EH) respectively. One of the haplotypes from WH was shared with the population of Pamir plateau, suggesting historical maternal connectivity between these areas. The phylogenetic analyses split the blue sheep into two paraphyletic clades, and western and eastern populations of IHR were within the Pamir and Tibetan plateau clades, respectively. We observed a relatively higher mean sequence divergence in the EH population than in the WH.
We propose five 'Evolutionary Significant Units' across the blue sheep distribution range based on observed variation in the species' ecological requirements, orography, climatic conditions, and maternal lineages, viz.; Western Himalaya-Pamir plateau (WHPP); Eastern Himalaya-Tibetan plateau (EHTP); Qilian mountains; Helan mountains and Hengduan mountains population. Despite the small sample size, population divergence was observed across the IHR, therefore, we suggest a transboundary, collaborative study on comparative morphology, anatomy, ecology, behaviour, and population genetics using harmonized different genetic markers for identifying the overall taxonomic status of the blue sheep across its range for planning effective conservation strategies.
由于空间和环境异质性导致微进化，种群表现出局部适应特征的迹象。藏羚广泛分布于亚洲高山地区，是雪豹的主要猎物。这些山脉由于冰川和消融期、地形和降雨模式的不同而具有不同的进化历史，这些因素导致物种多样化。
因此，我们使用线粒体细胞色素 b 基因（220bp）评估了印度喜马拉雅地区（IHR）藏羚的系统地理状况及其与其他种群的关系。在所观察到的五个单倍型中，有两个和三个分别来自西喜马拉雅山脉（WH）和东喜马拉雅山脉（EH）。来自 WH 的一个单倍型与帕米尔高原的种群共享，表明这些地区之间存在历史上的母系联系。系统发育分析将藏羚分为两个并系群，IHR 的西部和东部种群分别属于帕米尔和青藏高原群。我们观察到 EH 种群的平均序列分歧相对较高。
我们根据该物种生态需求、地形、气候条件和母系谱系的观察到的变化，在藏羚的分布范围内提出了五个“具有重要进化意义的单位”，即：西喜马拉雅山脉-帕米尔高原（WHPP）；东喜马拉雅山脉-青藏高原（EHTP）；祁连山；贺兰山和横断山脉种群。尽管样本量较小，但在 IHR 内观察到了种群分歧，因此，我们建议进行跨界合作研究，使用不同的遗传标记进行比较形态学、解剖学、生态学、行为学和群体遗传学研究，以确定藏羚在其范围内的整体分类地位，为制定有效的保护策略提供参考。
