中亚复杂的造山历史和结构,再加上更新世冰川周期,产生了逐步的干旱化。这些事件将极大地影响干旱中亚(ACA)许多中纬度物种的进化。在这项研究中,我们使用了两个线粒体基因(CO1和ND2)和全基因组SNP,再加上生态位建模,为了调查广泛分布的蜥蜴Phrynocepahlushelioscopus中的血统多样化和历史人口统计,以及它们与地理和过去气候变化的联系。我们从已知蜥蜴范围内的96个地方获得了300个个体的themtDNA数据集,其中,来自27个地区的51例个体被选择用于通过基因分型测序方法生成SNP数据集.连接的mtDNA数据集的系统发育分析揭示了八个地理相关的谱系,CO1基因的差异为4.21-10.41%,据估计,它们在447万年前已经合并。然而,我们观察到关于进化枝V(P.Helioscopussergeevi)来自塔吉克斯坦。祖传面积估计表明,日镜假单胞菌起源于费尔干纳山谷,然后散布到ACA的邻近地区,并有多个异同发散过程的历史,这表明Fergana可能是螺旋藻多样化的摇篮。上新世晚期中亚干旱化的加剧可能促进了这种适应干旱的蜥蜴在整个广阔领土上的快速辐射。随后,地质事件(例如,Hissar-Alay的隆起,侵犯里海)和地理障碍(例如,阿姆河,Zerarshan河)在更新世期间引发了螺旋藻的逐渐多样化。有趣的是,分支VIII(P.Helioscopusvarius)经历了快速的人口增长以及范围扩大,而CladeIV(P.Helioscopuscameranoi)在最后一次冰川最大期间经历了与范围收缩相关的急剧人口扩张。在CladeIV中,但不是在支教八世,与地理距离相比,环境周转对线粒体遗传独特性的贡献更大。总的来说,SNP数据集表明,地理距离比环境距离发挥更大的作用。mtDNA数据集和SNP数据集都表明CladeIV和CladeVIII的局部尺度遗传分化,揭示了伊犁河谷和准噶尔盆地的潜在地理障碍,分别。确定了与环境因素(降水和温度)相关的27个异常SNP,这支持了当地对干旱沙漠环境的适应。最后,我们的发现表明了分类学意义,例如支持塞达利维(II型进化枝)和子午线(I型进化枝)的完整物种地位。应根据进一步的证据以及增加的分类单元和地理采样进行未来的分析,以证实我们的发现。
The complex orogenic history and structure of Central Asia, coupled with Pleistocene glacial cycles have generated its stepwise aridification. Such events would have significantly influenced the evolution of many mid-latitude species in arid Central Asia (ACA). In this study, we employed two mitochondrial genes (CO1 and ND2) and genome-wide SNPs, coupled with ecological niche modeling, to investigate the lineage diversification and historical demography within a widespread lizard
Phrynocephalus helioscopus, and their associations with geography and past climate change. We obtained the mtDNA dataset for 300 individuals from 96 localities within the known range of the lizard, among which 51 individuals from 27 localities were selected for generating the SNP dataset via the genotyping-by-sequencing approach. Phylogenetic analyses of the concatenated mtDNA dataset revealed eight geographically correlated lineages that diverged by 4.21-10.41% for the CO1 gene, which were estimated to have coalesced ∼4.47 million years ago. However, we observed mito-nuclear discordance pattern regarding the population of Clade V (P. helioscopus sergeevi) from Tajikistan. Ancestral area estimations suggested that P. helioscopus originated from the Fergana Valley and then dispersed into the adjacent areas in ACA along with a history of multiple allopatric divergence processes, suggesting that Fergana may have been the cradle of diversification of P. helioscopus. The intensification of aridification across Central Asia during the Late Pliocene may have facilitated the rapid radiation of this arid-adapted lizard throughout this vast territory. Subsequently, the geological events (e.g., uplift of the Hissar-Alay, transgressions of the Caspian Sea) and geographic barriers (e.g., Amu Darya River, Zeravshan River) during the Pleistocene triggered the progressive diversification of P. helioscopus. Interestingly, Clade VIII (P. helioscopus varius) experienced rapid population growth coupled with range expansion while Clade IV (P. helioscopus cameranoi) underwent drastic population expansion associated with range contraction during the Last Glacial Maximum. In Clade IV, but not in Clade VIII, environmental turnover contributes more to mitochondrial genetic distinctiveness than geographic distance. Overall, the SNP dataset demonstrates that geographic distance plays a greater role than environmental distance. Both the mtDNA dataset and the SNP dataset suggest local-scale genetic differentiation in Clade IV and Clade VIII, revealing potential geographic barriers in the Ili River Valley and the Junggar Basin, respectively. Twenty-seven outlier SNPs associated with environmental factors (precipitation and temperature) were identified, which supports the signature of local adaptation to the arid desert environment. Finally, our finding suggests taxonomic implications, such as support for full species status for P. saidalievi (Clade II) and P. meridionalis (Clade I). Future analyses based on further evidence and increased taxon and geographic sampling should be carried out to corroborate our findings.