Institute of Animal Breeding and Genetics, Justus-Liebig-University of Gießen, Gießen, Germany.
Ecole des Sciences et Techniques de Production Animale, Faculté des Sciences Agronomiques, Université d'Abomey-Calavi, Cotonou, Bénin.
J Anim Breed Genet. 2020 Nov;137(6):622-640. doi: 10.1111/jbg.12495. Epub 2020 Jul 16.
The indigenous cattle population of Benin is a diverse mix of taurine and hybrid breeds shaped by diverse ecological and climatic conditions with eight agro-ecological zones (AEZ). Presumably, the taurine breeds face current endangerment due to ongoing indicine introgression following climate change and transboundary transhumance. The aim of the study was to investigate the genetic diversity and population structure of the indigenous breeds Lagune, Somba, Pabli and Borgou considering spatial agro-ecological and socio-economic factors (transhumance) based on 50k SNP and microsatellite data. Among the four sampled breeds, six genetic clusters were identified using model-free (discriminant analysis of principal components) and model-based (TESS and ADMIXTURE) methods separating taurine from hybrid breeds. Results based on an extension with publicly available historic SNP data sets from taurine and indicine West African cattle and additional outgroups provided additional insight into changes of genetic structure in the sampled breeds over time. Both taurine breeds, Somba and Lagune, showed a stable foundation but also spatially limited partial indicine introgression associated with transhumance leading to high genetic diversity. In addition, we found evidence for spatial diversity and changes in genetic structure over time in the Borgou breed in comparison of our samples with the historic samples which could be explained by potential continuous indicine introgression into the Borgou breed in two sample regions. Results for the Pabli breed do not conclusively point to full absorbance by the Borgou in comparison with all available Borgou samples. Further research is needed in this regard.
贝宁的本土牛种群是由多样化的生态和气候条件塑造的，包括 8 个农业生态区（AEZ）的瘤牛和杂交品种的混合体。据推测，由于气候变化和跨境迁徙导致的印度牛基因渗入，瘤牛品种目前正面临濒危。本研究的目的是基于 50k SNP 和微卫星数据，调查拉古纳、索巴、帕布利和博尔古等本土品种的遗传多样性和种群结构，考虑到空间农业生态和社会经济因素（迁徙）。在所分析的四个品种中，使用无模型（主成分判别分析）和基于模型（TESS 和 ADMIXTURE）的方法，确定了六个遗传聚类，将瘤牛品种与杂交品种区分开来。基于对来自西非瘤牛和印度牛的公开历史 SNP 数据集的扩展，以及其他外群的结果，进一步了解了样本品种在时间上遗传结构的变化。两种瘤牛品种，即索巴和拉古纳，显示出稳定的基础，但也存在与迁徙相关的空间有限的部分印度牛基因渗入，导致了高遗传多样性。此外，与我们的样本相比，在博尔古品种中发现了遗传结构随时间的空间多样性和变化的证据，这可以解释为两个样本区域中博尔古品种可能存在持续的印度牛基因渗入。与所有可用的博尔古样本相比，帕布利品种的结果并没有明确表明其完全被博尔古吸收。在这方面需要进一步的研究。
