Chen Qing, Lin Hongzhou, Zheng Chenqing, Mudrik Elena A, Kashentseva Tatiana A, Cheng Yalin, Wang Zhiru, Zhou Haiyan, Zhou Haixiang, Wang Wenjuan, Liu Yang
Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Center for Watershed Ecology, School of Life Sciences, Nanchang University, Nanchang, China.
School of Ecology, Sun Yat-Sen University, Shenzhen, China.
Mol Ecol. 2025 Jan;34(2):e17606. doi: 10.1111/mec.17606. Epub 2024 Dec 17.
To ensure the success of genetic rescue, we must minimise the potential negative effects of outbreeding depression that may arise from selecting source populations. The difficulty in assessing the likelihood of outbreeding depression has hindered its consideration in endangered species conservation. However, genomic research offers feasible indications. Here, we conduct conservation genomic analyses on the East Asian (EA) population and the relict Western/Central Asian (WCA) population of the critically endangered Siberian crane (Leucogeranus leucogeranus). We aim to assess genetic rescue's potential advantages and disadvantages between the two populations. Our analysis shows genomic evidence of limited genetic differentiation between them. The persistent decline in population size due to historical climatic oscillations leads to a decrease in genetic diversity and an increase in inbreeding. The WCA population has excessive deleterious homozygous mutations than the EA population, suggesting suffering from inbreeding depression resulting from less effective purifying selection. Forward simulations support the increase in genetic load due to elevated levels of inbreeding compromises fitness during population collapse. We strongly recommend an urgent genetic rescue for the WCA population through population supplementation from the EA population. However, the continuous monitoring of fitness outcomes is required through captive breeding. This work provides useful insights into the genetic management of a critically endangered species and emphasises the importance of evaluating the likelihood of outbreeding depression through genomic approaches.
为确保基因拯救的成功，我们必须尽量减少因选择源种群而可能产生的远交衰退的潜在负面影响。评估远交衰退可能性的困难阻碍了其在濒危物种保护中的考量。然而，基因组研究提供了可行的线索。在此，我们对极度濒危的白鹤（Leucogeranus leucogeranus）的东亚（EA）种群和残存的西亚/中亚（WCA）种群进行了保护基因组分析。我们旨在评估两个种群之间基因拯救的潜在利弊。我们的分析显示了它们之间有限的遗传分化的基因组证据。由于历史气候振荡导致种群数量持续下降，进而导致遗传多样性降低和近亲繁殖增加。WCA种群比EA种群有更多有害的纯合突变，这表明其因净化选择效率较低而遭受近亲繁殖衰退。正向模拟支持了在种群崩溃期间，近亲繁殖水平升高导致遗传负荷增加，从而损害了适应性。我们强烈建议通过从EA种群进行种群补充，对WCA种群进行紧急基因拯救。然而，需要通过圈养繁殖持续监测适应性结果。这项工作为极度濒危物种的遗传管理提供了有用的见解，并强调了通过基因组方法评估远交衰退可能性的重要性。
