Department of Entomology, University of Minnesota, 1980 Folwell Ave., St. Paul, MN, 55108, USA.
Mol Genet Genomics. 2020 Jul;295(4):891-909. doi: 10.1007/s00438-020-01662-0. Epub 2020 Mar 18.
Wolbachia is an obligate intracellular Gram-negative alpha-proteobacterium that has diverse effects on reproduction of arthropod hosts, including cytoplasmic incompatibility, male killing, feminization, and parthenogenesis. Some of these effects have important potential for control of insect pests, including mosquitoes that vector pathogens of humans. In mosquitoes, and in most other arthropods, elimination of Wolbachia by antibiotic treatment has no effect on host survival and reverses the Wolbachia-associated phenotype. Elimination of Wolbachia strain wFol, which enables parthenogenetic reproduction of the Collembolan, Folsomia candida, would result in population extinction. However, F. candida adults remain viable and resume reproduction when antibiotics are removed, suggesting that wFol survives antibiotic treatment in a quiescent persister state similar to that induced by chromosomally encoded toxin-antitoxin (TA) modules in free-living bacteria. Computational approaches were used to document the presence of antitoxin genes upstream of Wolbachia RelE/ParE, Fic, and AbiEii toxin genes. Moreover, this analysis revealed that Wolbachia RatA toxin is encoded by a single copy gene associated with an ssrS noncoding RNA gene. Documentation of potentially functional TA modules expands our understanding of the metabolic capabilities of Wolbachia, and provides an explanation for variable and sometimes contradictory results of antibiotic treatments. The presence of chromosomal TA modules in Wolbachia genomes suggests that wFol, and potentially other strains of Wolbachia, can enter a quiescent persister state.
沃尔巴克氏体是一种专性细胞内革兰氏阴性α-变形菌，对节肢动物宿主的生殖有多种影响，包括细胞质不相容、雄性致死、雌性化和孤雌生殖。其中一些效应具有控制害虫的重要潜力，包括传播人类病原体的蚊子。在蚊子和大多数其他节肢动物中，抗生素处理消除沃尔巴克氏体对宿主存活没有影响，并逆转与沃尔巴克氏体相关的表型。消除使弹尾目昆虫 Collembola 粉螨（Folsomia candida）能够进行孤雌生殖的沃尔巴克氏体菌株 wFol 将导致种群灭绝。然而，当抗生素被去除时，F. candida 成虫仍然存活并恢复繁殖，这表明 wFol 在类似于游离细菌中染色体编码的毒素-抗毒素 (TA) 模块诱导的休眠持久状态下在抗生素处理中存活。计算方法用于记录沃尔巴克氏体 RelE/ParE、Fic 和 AbiEii 毒素基因上游的抗毒素基因的存在。此外，该分析表明，沃尔巴克氏体 RatA 毒素由与 ssrS 非编码 RNA 基因相关的单个拷贝基因编码。潜在功能 TA 模块的记录扩展了我们对沃尔巴克氏体代谢能力的理解，并为抗生素处理的可变和有时矛盾的结果提供了解释。染色体 TA 模块在沃尔巴克氏体基因组中的存在表明，wFol 并且可能其他沃尔巴克氏体菌株可以进入休眠持久状态。
