Colangelo Paolo, Di Civita Marika, Bento Carlos M, Franchini Paolo, Meyer Axel, Orel Nadiya, das Neves Luis C B G, Mulandane Fernando C, Almeida Joao S, Senczuk Gabriele, Pilla Fabio, Sabatelli Simone
National Research Council, Research Institute on Terrestrial Ecosystems, Via Salaria km 29.300, 00015, Montelibretti (Roma), Italy.
Department of Agricultural, Environmental and Food Sciences, University of Molise, 86100, Campobasso, Italy.
BMC Ecol Evol. 2024 Mar 4;24(1):29. doi: 10.1186/s12862-024-02209-2.
The African buffalo, Syncerus caffer, is a key species in African ecosystems. Like other large herbivores, it plays a fundamental role in its habitat acting as an ecosystem engineer. Over the last few centuries, African buffalo populations have declined because of range contraction and demographic decline caused by direct or indirect human activities. In Mozambique, historically home to large buffalo herds, the combined effect of colonialism and subsequent civil wars has created a critical situation that urgently needs to be addressed. In this study, we focused on the analysis of genetic diversity of Syncerus caffer caffer populations from six areas of Mozambique. Using genome-wide SNPs obtained from ddRAD sequencing, we examined the population structure across the country, estimated gene flow between areas under conservation management, including national reserves, and assessed the inbreeding coefficients. Our results indicate that all studied populations of Syncerus caffer caffer are genetically depauperate, with a high level of inbreeding. Moreover, buffaloes in Mozambique present a significant population differentiation between southern and central areas. We found an unexpected genotype in the Gorongosa National Park, where buffaloes experienced a dramatic population size reduction, that shares a common ancestry with southern populations of Catuane and Namaacha. This could suggest the past occurrence of a connection between southern and central Mozambique and that the observed population structuring could reflect recent events of anthropogenic origin. All the populations analysed showed high levels of homozygosity, likely due to extensive inbreeding over the last few decades, which could have increased the frequency of recessive deleterious alleles. Improving the resilience of Syncerus caffer caffer in Mozambique is essential for preserving the ecosystem integrity. The most viable approach appears to be facilitating translocations and re-establishing connectivity between isolated herds. However, our results also highlight the importance of assessing intraspecific genetic diversity when considering interventions aimed at enhancing population viability such as selecting suitable source populations.
非洲水牛（学名：Syncerus caffer）是非洲生态系统中的关键物种。与其他大型食草动物一样，它作为生态系统工程师，在其栖息地发挥着重要作用。在过去几个世纪里，由于直接或间接的人类活动导致栖息地缩小和种群数量下降，非洲水牛的数量减少。在历史上曾有大量水牛群的莫桑比克，殖民主义和随后的内战共同造成了危急局面，亟待解决。在本研究中，我们重点分析了来自莫桑比克六个地区的非洲水牛指名亚种（Syncerus caffer caffer）的遗传多样性。利用从简化基因组测序（ddRAD测序）获得的全基因组单核苷酸多态性（SNP），我们研究了全国的种群结构，估计了包括国家保护区在内的受保护管理区域之间的基因流动，并评估了近亲繁殖系数。我们的结果表明，所有研究的非洲水牛指名亚种种群的遗传多样性都很低，近亲繁殖程度很高。此外，莫桑比克的水牛在南部和中部地区存在显著的种群分化。我们在戈龙戈萨国家公园发现了一个意外的基因型，那里的水牛种群数量急剧减少，该基因型与南部的卡图阿内和纳马阿查种群有共同的祖先。这可能表明莫桑比克南部和中部过去存在联系，且观察到的种群结构可能反映了近期人为起源的事件。所有分析的种群都表现出高度的纯合性，这可能是由于过去几十年广泛的近亲繁殖，增加了隐性有害等位基因的频率。提高莫桑比克非洲水牛指名亚种的恢复力对于维护生态系统的完整性至关重要。最可行的方法似乎是促进种群迁移，并重新建立孤立种群之间的连通性。然而，我们的结果也凸显了在考虑旨在提高种群生存能力的干预措施（如选择合适的源种群）时，评估种内遗传多样性的重要性。
