Greater Phage Genotypic Diversity Constrains Arms-Race Coevolution.
Greater Phage Genotypic Diversity Constrains Arms-Race Coevolution.
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DOI：
10.3389/fcimb.2022.834406
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发表时间：
2022
影响因子：
5.7
通讯作者：
Padfield D
中科院分区：
文献类型：
--
作者：
Castledine M;Sierocinski P;Inglis M;Kay S;Hayward A;Buckling A;Padfield D
宿主与寄生虫之间的拮抗协同进化，即宿主抗性和寄生虫感染性的相互进化，在生态学和进化中具有重要意义。共同进化的动力学，特别是宿主或寄生虫是否有一个进化的共同点，在很大程度上受到宿主抗性和寄生虫感染性性状的相对遗传变异量的影响。虽然研究已经在共同进化过程中操纵了遗传多样性，例如通过增加突变率，但尚不清楚启动遗传多样性如何影响宿主-寄生虫共同进化。在这里，我们（共同）进化的细菌荧光假单胞菌SBW 25和两个噬菌体基因型的裂解噬菌体SBW 25 - 2在隔离（一个噬菌体基因型）和在一起（两个噬菌体基因型）。细菌种群迅速进化出噬菌体抗性，噬菌体抗性增加了它们的感染性。当噬菌体群体与细菌分离进化时，细菌抗性和噬菌体感染性随着时间的推移而增加，表明军备竞赛共同进化。相比之下，当两种噬菌体基因型在一起时，细菌不会响应于增加的噬菌体感染性而增加其抗性。这可能是由于细菌无法通过相同的突变进化出对两种噬菌体的抗性。这些结果表明，增加初始寄生虫的基因型多样性可以给寄生虫的进化优势，逮捕长期的共同进化。这项研究具有重要意义的应用噬菌体在噬菌体治疗和理解宿主寄生虫的动力学在更广泛的生态和进化理论。
Antagonistic coevolution between hosts and parasites, the reciprocal evolution of host resistance and parasite infectivity, has important implications in ecology and evolution. The dynamics of coevolution—notably whether host or parasite has an evolutionary advantage—is greatly affected by the relative amount of genetic variation in host resistance and parasite infectivity traits. While studies have manipulated genetic diversity during coevolution, such as by increasing mutation rates, it is unclear how starting genetic diversity affects host–parasite coevolution. Here, we (co)evolved the bacterium Pseudomonas fluorescens SBW25 and two bacteriophage genotypes of its lytic phage SBW25ɸ2 in isolation (one phage genotype) and together (two phage genotypes). Bacterial populations rapidly evolved phage resistance, and phage reciprocally increased their infectivity in response. When phage populations were evolved with bacteria in isolation, bacterial resistance and phage infectivity increased through time, indicative of arms-race coevolution. In contrast, when both phage genotypes were together, bacteria did not increase their resistance in response to increasing phage infectivity. This was likely due to bacteria being unable to evolve resistance to both phage via the same mutations. These results suggest that increasing initial parasite genotypic diversity can give parasites an evolutionary advantage that arrests long-term coevolution. This study has important implications for the applied use of phage in phage therapy and in understanding host–parasite dynamics in broader ecological and evolutionary theory.