Department of Zoology, University of Oxford, 11a Mansfield Road, Oxford, OX1 3SZ, UK.
Eawag, Überlandstrasse 133, CH-8600 Dübendorf, Switzerland.
Proc Biol Sci. 2020 Jun 24;287(1929):20200562. doi: 10.1098/rspb.2020.0562. Epub 2020 Jun 17.
Many microbial symbionts have multiple phenotypic consequences for their animal hosts. However, the ways in which different symbiont-mediated phenotypes combine to affect fitness are not well understood. We investigated whether there are correlations between different symbiont-mediated phenotypes. We used the symbiont , a striking example of a bacterial symbiont conferring diverse phenotypes on insect hosts. We took 11 strains of infecting pea aphids () and assessed their ability to provide protection against the fungal pathogen and the parasitoids and . We also assessed effects on male offspring production for five of the strains. All but one of the strains provided very strong protection against the parasitoid . As previously reported, variable protection against and was also present; male-killing was likewise a variable phenotype. We find no evidence of any correlation, positive or negative, between the different phenotypes, nor was there any evidence of an effect of symbiont phylogeny on protective phenotype. We conclude that multiple symbiont-mediated phenotypes can evolve independently from one another without trade-offs between them.
许多微生物共生体对其动物宿主有多种表型后果。然而，不同共生体介导的表型如何组合来影响适应性还不是很清楚。我们调查了不同共生体介导的表型之间是否存在相关性。我们使用共生体，这是一个细菌共生体赋予昆虫宿主多种表型的显著例子。我们采用了感染豌豆蚜的 11 株 ，并评估了它们提供对真菌病原体 和寄生蜂 和 的保护的能力。我们还评估了其中 5 株 的对雄性后代产生的影响。除了一株之外，所有的 株都能非常有效地抵抗寄生蜂 。正如之前报道的，对 和 的可变保护也存在；雄性致死同样是一个可变的表型。我们没有发现任何正相关或负相关的证据，也没有发现共生体系统发育对保护表型有任何影响。我们得出结论，多个共生体介导的表型可以彼此独立地进化，而不需要它们之间进行权衡。
