Pimentel André C, Cesar Cássia S, Martins Arthur H B, Martins Marcos, Cogni Rodrigo
Department of Ecology, University of São Paulo, São Paulo, Brazil.
Microb Ecol. 2025 Apr 9;88(1):24. doi: 10.1007/s00248-025-02518-z.
Wolbachia pipientis is a maternally transmitted endosymbiont infecting more than half of terrestrial arthropod species. Wolbachia can express parasitic phenotypes such as manipulation of host reproduction and mutualist phenotypes such as protection against RNA virus infections. Because Wolbachia can invade populations by reproductive manipulation and block virus infection, it is used to modify natural insect populations. However, the ecological importance of virus protection is not yet clear, especially due to scarce information on Wolbachia protection against viruses that are common in nature. We used systemic infection to investigate whether Wolbachia protects its host by suppressing the titer of DMELDAV and DMelNora virus, two viruses that commonly infect Drosophila melanogaster flies in natural populations. Antiviral protection was tested in three systems to assess the impact of Wolbachia strains across species: (1) a panel of Wolbachia strains transfected into Drosophila simulans, (2) two Wolbachia strains introgressed into the natural host D. melanogaster, and (3) two native Wolbachia strains in their natural hosts Drosophila baimaii and Drosophila tropicalis. We showed that certain Wolbachia strains provide protection against DMelNora virus and DMELDAV, and this protection is correlated with Wolbachia density, which is consistent with what has been observed in protection against other RNA viruses. Additionally, we found that Wolbachia does not protect its original host, D. melanogaster, from DMELDAV infection. While native Wolbachia can reduce DMELDAV titers in D. baimaii, this effect was not detected in D. tropicalis. Although the Wolbachia protection-induced phenotype seems to depend on the virus, the specific Wolbachia strain, and the host species, our findings suggest that antiviral protection may be one of the mutualistic effects that helps explain why Wolbachia is so widespread in arthropod populations.
嗜菌胞属（Wolbachia pipientis）是一种通过母体传播的内共生菌，感染了超过半数的陆生节肢动物物种。嗜菌胞属能够表现出寄生表型，如操控宿主繁殖，也能表现出互利共生表型，如抵御RNA病毒感染。由于嗜菌胞属能够通过繁殖操控入侵种群并阻止病毒感染，因此它被用于改变天然昆虫种群。然而，病毒防护的生态重要性尚不清楚，尤其是因为关于嗜菌胞属抵御自然界常见病毒的信息稀缺。我们利用全身感染来研究嗜菌胞属是否通过抑制DMELDAV和DMelNora病毒的滴度来保护其宿主，这两种病毒在自然种群中通常感染黑腹果蝇（Drosophila melanogaster）。在三个系统中测试了抗病毒保护作用，以评估不同物种中嗜菌胞属菌株的影响：（1）一组转染到拟果蝇（Drosophila simulans）中的嗜菌胞属菌株；（2）两种渗入天然宿主黑腹果蝇的嗜菌胞属菌株；（3）两种天然宿主白带果蝇（Drosophila baimaii）和热带果蝇（Drosophila tropicalis）中的天然嗜菌胞属菌株。我们发现某些嗜菌胞属菌株能够抵御DMelNora病毒和DMELDAV，并且这种保护作用与嗜菌胞属的密度相关，这与在抵御其他RNA病毒中观察到的情况一致。此外，我们发现嗜菌胞属不能保护其原始宿主黑腹果蝇免受DMELDAV感染。虽然天然嗜菌胞属能够降低白带果蝇中DMELDAV的滴度，但在热带果蝇中未检测到这种效果。尽管嗜菌胞属保护诱导的表型似乎取决于病毒、特定的嗜菌胞属菌株和宿主物种，但我们的研究结果表明，抗病毒保护可能是一种互利共生效应，有助于解释为什么嗜菌胞属在节肢动物种群中如此广泛分布。
