International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya.
School of Pure and Applied Sciences, Department of Biochemistry, Biotechnology and Microbiology, Kenyatta University, P.O. Box 43844-00100, Nairobi, Kenya.
Naturwissenschaften. 2021 Apr 19;108(3):17. doi: 10.1007/s00114-021-01729-x.
The honeybee, Apis mellifera, is a globally distributed species that has spread both naturally and by humans across the globe resulting in many natural and secondary contact zones. The geographic isolation of honeybees is likely to contribute to genetic differentiation. Secondary contact has resulted in hybridization at the nuclear genome, but replacement of mitochondrial. Here, we used a mitochondrial marker and 19 microsatellite markers to test for the variations in the mitochondrial and nuclear genomes of honeybee populations on the Comoros islands. We used samples of 160 workers for mtDNA analysis and 288 workers from 16 colonies spread across the three islands for microsatellite analyses. Our results showed that the wild honeybee populations of the Comoros Islands consist of coexisting mitochondrial haplotypes. One belongs to the typical African A-lineage, and the other, the newly described L-lineage, is closely related to Apis koschevnikovi, a honeybee species native to Southeast Asia. The nuclear genomes show complete hybridization, high genetic diversity, and strong differentiation according to the island of origin. Based on our results, we hypothesise that the Asian honeybee could have been transported from Southeast Asia to Madagascar and Comoros via the human migrations that occurred 6000 years ago, and has hybridised with African honeybees at the nuclear genome, but maternal ancestry still can be traced using the mtDNA markers. We conclude that mtDNA plays a pivotal role in adaptation to the local environment, with both haplotypes of the honeybees of Comoros contributing significantly to the mito-nuclear coadaptation resulting in maintenance at almost equal frequency.
蜜蜂，Apis mellifera，是一种分布广泛的物种，无论是自然迁徙还是人类的迁徙，都使其遍布全球，从而形成了许多自然和次生接触区。蜜蜂的地理隔离可能导致遗传分化。次生接触导致了核基因组的杂交，但线粒体被取代。在这里，我们使用一个线粒体标记和 19 个微卫星标记来测试科摩罗群岛上的蜜蜂种群的线粒体和核基因组的变化。我们使用了 160 只工蜂的样本进行 mtDNA 分析，以及来自 16 个殖民地的 288 只工蜂进行微卫星分析。我们的结果表明，科摩罗群岛的野生蜜蜂种群由共存的线粒体单倍型组成。一个属于典型的非洲 A 谱系，另一个是新描述的 L 谱系，与原产于东南亚的蜜蜂物种 Apis koschevnikovi 密切相关。核基因组显示完全杂交、高度遗传多样性和根据起源岛的强烈分化。根据我们的结果，我们假设亚洲蜜蜂可能是在 6000 年前人类迁徙的过程中从东南亚传播到马达加斯加和科摩罗的，并且与非洲蜜蜂在核基因组中发生了杂交，但母系遗传仍可以通过 mtDNA 标记来追踪。我们得出结论，mtDNA 在适应当地环境方面起着关键作用，科摩罗蜜蜂的两种单倍型都对导致线粒体-核共适应的维持做出了重要贡献，其频率几乎相等。
