Department of Life Sciences, Imperial College London, London, UK.
Sci Rep. 2024 Nov 27;14(1):29467. doi: 10.1038/s41598-024-80887-0.
Isolation mechanisms between mosquito species of the Anopheles gambiae complex, which includes major malaria vectors, remain poorly understood. In some cases, pre-zygotic barriers have been shown to limit gene flow between species of the complex, leading to a low level of hybridisation in nature. Post-zygotic mechanisms manifest with F hybrid males fully sterile and F hybrid females with reduced fertility. Genetic approaches combined with DNA sequencing techniques have highlighted the involvement of genomic regions in hybrid incompatibility with a predominant role of the X chromosome. In addition, differences in the phenotype of F hybrid males have been identified depending on the directionality of the parental cross used to generate them. All these studies have focused on the interaction of nuclear DNA elements in hybrid individuals. Given the role that mitochondrial DNA plays in genetic incompatibilities within other organisms and its unique inheritance pattern, commonly maternal, we conducted a genetic study that relied on the introgression of mitochondrial DNA between Anopheles gambiae and Anopheles arabiensis. The findings indicate that the mitochondrial switch does not appear to restore the fertility of F hybrid males, suggesting that mitochondrial DNA may not play a role in hybrid incompatibilities in these Anopheles species.
按蚊复合体（包括主要疟疾媒介）中蚊种间的隔离机制仍了解甚少。在某些情况下，已证明前合子障碍限制了复合体中种间的基因流动，导致自然界中杂交水平较低。合子后机制表现为 F1 杂种雄性完全不育，F1 杂种雌性生育力降低。遗传方法与 DNA 测序技术相结合，强调了基因组区域在杂种不亲和性中的作用，X 染色体起着主要作用。此外，还根据产生它们的亲本杂交的方向性，确定了 F1 杂种雄性表型的差异。所有这些研究都集中在杂种个体中核 DNA 元素的相互作用上。鉴于线粒体 DNA 在其他生物体中的遗传不兼容性以及其独特的遗传模式（通常为母系遗传）中的作用，我们进行了一项遗传研究，该研究依赖于将线粒体 DNA 导入冈比亚按蚊和阿拉伯按蚊之间。研究结果表明，线粒体转换似乎并没有恢复 F1 杂种雄性的生育能力，这表明在线粒体 DNA 可能不会在这些按蚊物种的杂种不亲和性中发挥作用。
