Numajiri Yuko, Kondo Natsuko I, Toquenaga Yukihiko, Kageyama Daisuke
Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 1-2 Owashi, Tsukuba, Ibaraki, Japan.
Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.
Heredity (Edinb). 2025 Aug;134(8):512-518. doi: 10.1038/s41437-025-00787-5. Epub 2025 Jul 30.
Cytoplasmic incompatibility (CI) is a phenomenon where embryonic development is disrupted-often leading to complete failure-when the female parent lacks the symbiont strain carried by the male parent. This mechanism, employed by maternally transmitted symbionts such as Wolbachia, facilitates their rapid spread within a host population. CI has significant potential as a tool for achieving population replacement or suppression, particularly targeting disease vectors and agricultural pests. While complete expression of CI is ideal for such applications, its intensity can vary. Despite extensive research on the symbiont genotypes, the influence of host genetic background on CI expression remains poorly understood. Here, we found that in the bean beetle Callosobruchus analis, the Wolbachia strain wCana2 induces weak CI in its native nuclear background but strong CI in a previously unassociated nuclear background. Crossing experiments reveal that the nuclear backgrounds of both male and female parents can significantly affect CI expression independent of Wolbachia titres in C. analis. These findings uncover novel perspectives on the host-symbiont interactions underlying CI and highlight the complexities to be addressed for its practical application.
细胞质不亲和（CI）是一种现象，即当母本缺乏父本携带的共生菌菌株时，胚胎发育会受到干扰，通常会导致完全失败。这种由诸如沃尔巴克氏体等母系传播的共生菌所采用的机制，促进了它们在宿主种群中的快速传播。CI作为一种实现种群替代或抑制的工具具有巨大潜力，特别是针对病媒和农业害虫。虽然CI的完全表达对于此类应用是理想的，但其强度可能会有所不同。尽管对共生菌基因型进行了广泛研究，但宿主遗传背景对CI表达的影响仍知之甚少。在这里，我们发现，在豆象Callosobruchus analis中，沃尔巴克氏体菌株wCana2在其原生核背景中诱导较弱的CI，但在以前未关联的核背景中诱导较强的CI。杂交实验表明，在豆象中，父母本的核背景均可显著影响CI表达，而与沃尔巴克氏体滴度无关。这些发现揭示了CI背后宿主-共生菌相互作用的新观点，并突出了其实际应用中需要解决的复杂性。
