Abstract:
Oak gall wasps typically exhibit a life cycle with one sexual and one asexual generation each year. These wasps can carry various endosymbionts, one of which is the maternally inherited bacterium Wolbachia that can induce several reproductive manipulations on its host. Cytoplasmic incompatibility (CI) has been described as the most prominent of these manipulations. CI leads to embryonic mortality in the hosts\' offspring when infected males mate with either uninfected females or with females that harbour different Wolbachia strains. It has been hypothesized that Wolbachia can induce CI in oak gall wasps. To address this hypothesis, we derived a mathematical model to investigate the spread of a bacterial infection in naive populations and to determine the plausibility of CI occurrence. To validate our model, we used published data from Wolbachia-infected Belonocnema kinseyi populations in two approaches. Our first approach uses measurements of infection frequencies and maternal transmission in the sexual generation. For the second approach, we extended the model to compare predictions to estimates of mtDNA-haplotypes, which, like Wolbachia, are maternally inherited, and can therefore be associated with the infection. Both approaches indicate that CI is present in these populations. Our model can be generalized to investigate the occurrence of CI not only for oak gall wasps but also for other species.
摘要:
橡树胆黄蜂通常表现出一个生命周期,每年有性和无性。这些黄蜂可以携带各种内共生体,其中之一是母系遗传的细菌Wolbachia,可以在其宿主上诱导多种生殖操作。细胞质不相容性(CI)已被描述为这些操作中最突出的。当受感染的雄性与未感染的雌性或带有不同Wolbachia菌株的雌性交配时,CI会导致宿主后代的胚胎死亡。有人假设Wolbachia可以在橡树胆黄蜂中诱导CI。为了解决这个假设,我们推导了一个数学模型来研究细菌感染在幼稚人群中的传播,并确定CI发生的合理性。为了验证我们的模型,我们在两种方法中使用了来自Wolbachia感染的Belonocnema治疗人群的公开数据。我们的第一种方法使用测量性世代中的感染频率和母体传播。对于第二种方法,我们扩展了模型,将预测与mtDNA单倍型的估计进行比较,which,比如Wolbachia,是母系遗传的,因此可能与感染有关。两种方法都表明CI存在于这些群体中。我们的模型可以推广以研究CI的发生,不仅适用于橡树胆黄蜂,而且适用于其他物种。