Karanja Patrick, Kinyua Johnson, Kingori Edward, Chiyo Patrick, Obanda Vincent, Lwande Olivia Wesula
Department of Biochemistry Jomo Kenyatta University of Agriculture and Technology (JKUAT) Nairobi Kenya.
Veterinary Service Department Kenya Wildlife Service Nairobi Kenya.
Ecol Evol. 2025 Jul 31;15(8):e71879. doi: 10.1002/ece3.71879. eCollection 2025 Aug.
Fences are increasingly used globally as a management tool in conservation to reduce wildlife depredations, disease transmission, and wildlife mortality. There are a limited number of studies on the genetic effects of perimeter fencing of protected areas on megaherbivores. Using population genetic analyses on 226 sequences of a 400 bp fragment of the mtDNA Dloop from 10 East African buffalo populations (3 fenced and 7 unfenced), the influence of spatial isolation and fencing on buffalo population genetic diversity and genetic differentiation was examined. Mean gene diversity between fenced and unfenced buffalo populations was not different (fenced: 0.978 ± 0.003, unfenced: 0.973 ± 0.004, = 0.300), but nucleotide diversity was higher in fenced than unfenced populations (fenced: 0.038 ± 0.019, unfenced: 0.030 ± 0.015, = 0.005). Genetic differentiation among buffalo populations based on haplotype frequencies and model-based genetic distance was weak (FST = 0.08, ΦST = 0.06) and contributed to 6.2% and 8.5% of total genetic variance, respectively. Ninety-three percent of population pairs were genetically differentiated by distances determined from haplotype frequencies, but only 51% of population pairs were differentiated using modeled distances, suggesting recent differentiation. There was no correlation between linearized FST and geographical distance ( = -0.005, = 0.52), but linearized ΦST was moderately correlated with geographic distance ( = 0.329, = 0.03). The distance effect was greater when fenced populations were excluded (ΦST: = 0.464, = 0.05), suggesting that insularization due to fencing is distorting isolation by distance. SSD analyses revealed that 2 of 3 fenced populations and 2 of 7 unfenced populations had non-unimodal distributions, suggesting demographically declining populations. Our study reveals the high genetic diversity but warns that genetic erosion due to isolation, including fencing, is likely setting in and will have an impact on East African buffalo populations.
在全球范围内，围栏越来越多地被用作保护管理工具，以减少野生动物的掠夺、疾病传播和野生动物死亡。关于保护区周边围栏对大型食草动物的遗传影响的研究数量有限。通过对来自10个东非水牛种群（3个有围栏，7个无围栏）的线粒体DNA D环400bp片段的226个序列进行群体遗传分析，研究了空间隔离和围栏对水牛种群遗传多样性和遗传分化的影响。有围栏和无围栏水牛种群之间的平均基因多样性没有差异（有围栏：0.978±0.003，无围栏：0.973±0.004，P = 0.300），但有围栏种群的核苷酸多样性高于无围栏种群（有围栏：0.038±0.019，无围栏：0.030±0.015，P = 0.005）。基于单倍型频率和基于模型的遗传距离的水牛种群间遗传分化较弱（FST = 0.08，ΦST = 0.06），分别占总遗传变异量的6.2%和8.5%。93%的种群对通过单倍型频率确定的距离在遗传上有差异，但使用模型距离时只有51%的种群对有差异，表明是近期的分化。线性化FST与地理距离之间没有相关性（P = -0.005，P = 0.52），但线性化ΦST与地理距离有中度相关性（P = 0.329，P = 0.03）。排除有围栏种群时距离效应更大（ΦST：P = 0.464，P = 0.05），这表明围栏导致的岛屿化正在扭曲距离隔离。SSD分析显示，3个有围栏种群中的2个和7个无围栏种群中的2个具有非单峰分布，表明种群数量在下降。我们的研究揭示了高遗传多样性，但警告说包括围栏在内的隔离导致的遗传侵蚀可能正在发生，并将对东非水牛种群产生影响。
