24小时热门版块排行榜

返回列表

晋鹏

版主 (知名作家)

应助: 626 (博士)
贵宾: 0.096
金币: 27590.2
散金: 1052
红花: 288
沙发: 2
帖子: 5663
在线: 726.4小时
虫号: 1183978
注册: 2011-01-05
性别: GG
专业: 生物信息学
管辖: 农林

[交流] [优秀文章推荐]中科院发现海拔最高的鱼类冰期避难所已有1人参与

Location and haploclade composition of each sampling site in this study. Pie charts exhibit the frequency of lineages or sublineages in each population

　　更新世以来，以冰期—间冰期回旋为主的气候波动，对生物的演化产生了重大的影响，是决定现生生物分布格局的重要因素，其中以最近一次的末次冰盛期的影响最为深远。冰期避难所是生物在冰期退守的栖息场所，也是冰期后物种重新扩散的起点。研究冰期避难所，对揭示不同生物区系之间的关系、了解物种的形成机制和进行生物多样性保护都具有重要意义，也为冰期与间冰期的研究提供了生物学证据。

Median-joining network of mitochondrial D-loop haplotypes for the five taxa of schizothoracine fish in this study

　　青藏高原及其周边是地球上除两极外冰川发育最为广泛的地区。淡水鱼类在冰期退缩和冰期后的扩散过程均受到水系的严格制约，因而是研究冰期对生物影响非常理想的对象。中国科学院水生生物研究所陈毅峰团队利用线粒体D-loop序列和12对微卫星标记，对青藏高原地区的裂腹鱼类进行了谱系地理格局的系统研究，揭示了藏北羌塘高原内流湖泊的裂腹鱼类具有比长江、澜沧江、怒江以及雅鲁藏布江等外流河的裂腹鱼类更高的遗传多样性和相对独立的遗传结构，否定了青藏高原腹地湖泊中的裂腹鱼类是冰期后经由外流河流扩散而来的可能性。在藏北高原的诸多内流湖泊中，色林错流域裂腹鱼类的种群遗传多样性最高、原始单倍型最为丰富、有效种群的扩张历史最久，始于末次冰盛期以前。而物种分布模型预测（SDM）也表明色林错流域在末次冰盛期具备了裂腹鱼类生存的基本气候条件。因此，海拔4540 m的色林错是在青藏高原腹地可以让鱼类度过末次冰盛期的避难所，这也是世界上已发现的海拔最高的冰期避难所。

Variation of the instantaneous population growth rate reconstructed by Bayesian skyline plot based on D-loop sequences

　　Pleistocene climatic oscillations have greatly influenced the evolutionary history and distribution pattern of most extant species. However, their effects on species on the Qinghai-Tibet Plateau (QTP) are not well understood. To investigate the effects of past climatic shifts, particularly the Last Glacial Maximum (LGM), on plateau fish, we analysed the phylogeographic structure and demographic history of five closely related taxa of the subfamily Schizothoracinae, a representative endemic taxon of the QTP, from nine endorheic lakes on the central QTP and three peripheral exorheic rivers using the mitochondrial control region (D-loop) sequence and 12 microsatellite (SSR) markers. Phylogram from D-loop haplotypes revealed two well-supported lineages (North and South) separated by the Tanggula Mountains. The results from the D-loop and SSR revealed that endorheic populations possess high genetic diversity and a unique genetic structure. The most recent demographic expansion occurred post-LGM for most endorheic populations and in the last interglacial period for Siling Co and all exorheic populations. Phylogeographic structure, together with species distribution modelling, supports the scenario of multiple glacial refugia on the QTP during the LGM and suggests that Siling Co (4540 m asl) is a cryptic glacial microrefugia for plateau fish, which would be the highest glacial microrefugia known.

回复此楼