Barber Alessa, Borsutzky Etje, Müller Caroline
Department of Chemical Ecology, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany.
Joint Institute for Individualisation in a Changing Environment (JICE), University of Münster and Bielefeld University, Bielefeld, Germany.
Sci Rep. 2025 Jul 9;15(1):24746. doi: 10.1038/s41598-025-10427-x.
Gregarines are often host-specific, share a long coevolution with their host and can be viewed on a parasitism-mutualism spectrum. However, little is known about whether impacts on their hosts depend on the infection history over generations and thus transgenerational effects, or rather on the recent infection status. In the mustard leaf beetle, Phaedon cochleariae, more negative than positive effects of the gregarine species Gregarina cochlearium on its host were found in individuals infected over several generations compared to recently gregarine-freed individuals. Here, we tested the effects of the infection history of previous generations and the current infection status (not infected or infected with gregarines) on the performance, consumption, behavior and surface profiles of P. cochleariae, using a full factorial design. The current infection alone and in interaction with the infection history affected some performance parameters; developmental time was most prolonged in short-term infected individuals, while survival was highest in long-term infected individuals. Under a current gregarine infection adult female body mass was reduced, while reproduction was neither affected by the current infection nor infection history. With regard to consumption-related traits, the current infection status affected the growth rate of both sexes (in females also in interaction with infection history) and the consumption index of males, being lowest in currently infected individuals. Currently infected individuals also showed slightly higher activity with regard to some of the measured traits, while boldness-related traits were unaffected. No changes were found in surface profiles in dependence of the gregarine infection status. Overall, under the used conditions, the past experience with gregarines over generations seems to have only little impact on P. cochleariae, while the current infection status causes plastic responses, with negative consequences mostly on development. The study highlights that gregarines modulate the phenotypes of their host in different traits.
簇虫通常具有宿主特异性，与宿主有着长期的协同进化关系，并且可以在寄生 - 共生的连续谱上被看待。然而，对于它们对宿主的影响是取决于多代的感染历史以及由此产生的跨代效应，还是更取决于近期的感染状态，我们所知甚少。在芥菜叶甲（Phaedon cochleariae）中，与近期未感染簇虫的个体相比，在多代感染簇虫物种（Gregarina cochlearium）的个体中发现，该簇虫对宿主的负面影响大于正面影响。在这里，我们使用全因子设计，测试了前代的感染历史和当前的感染状态（未感染或感染簇虫）对芥菜叶甲的性能、食量、行为和体表特征的影响。仅当前感染以及与感染历史的相互作用会影响一些性能参数；发育时间在短期感染的个体中延长最多，而长期感染的个体存活率最高。在当前感染簇虫的情况下，成年雌性体重降低，而繁殖既不受当前感染的影响，也不受感染历史的影响。关于与食量相关的性状，当前感染状态影响了两性的生长速率（在雌性中也与感染历史相互作用）以及雄性的食量指数，在当前感染的个体中最低。当前感染的个体在一些测量性状方面也表现出略高的活动水平，而与大胆程度相关的性状未受影响。未发现体表特征因簇虫感染状态而发生变化。总体而言，在所用条件下，过去多代感染簇虫的经历似乎对芥菜叶甲影响很小，而当前的感染状态会引发可塑性反应，主要对发育产生负面影响。该研究强调簇虫会调节其宿主不同性状的表型。
