The evolutionary dynamics of male-killers and their hosts
The evolutionary dynamics of male-killers and their hosts
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DOI：
10.1046/j.1365-2540.2000.00645.x
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发表时间：
2000-02-01
期刊：
影响因子：
3.8
通讯作者：
Hurst, LD
中科院分区：
文献类型：
--
作者：
Randerson, JP;Smith, NGC;Hurst, LD
杀雄细菌是一种细胞质性比扭曲剂，通过其昆虫宿主的雌性垂直传播。细菌杀死雄性宿主被认为是一种适应性细菌特性，因为它增强了携带这些细菌克隆亲属的雌性宿主的适应性。在这里，我们试图解释多个男性杀手在自然宿主种群的观察。首先，我们表明，这样的男性杀手多态性不能解释一个经典的男性杀人模型。然后，我们表明，更复杂的模型纳入宿主的抗性进化可以解释男性杀手多态性。然而，只有在抗性基因非常昂贵的情况下，这才有可能。我们还考虑了男性杀手的长期进化动力学，并表明，逐步更“高效”的男性杀手的进化可以通过宿主抗性的出现而受阻。抗性基因的存在可以使效率较低的雄性杀手胜过其竞争对手，从而扭转传播效率更高和宿主代谢负荷减少的趋势。
Male-killing bacteria are cytoplasmic sex-ratio distorters that are transmitted vertically through females of their insect hosts. The killing of male hosts by their bacteria is thought to be an adaptive bacterial trait because it augments the fitness of female hosts carrying clonal relatives of those bacteria. Here we attempt to explain observations of multiple male-killers in natural host populations. First we show that such male-killer polymorphism cannot be explained by a classical model of male-killing. We then show that more complicated models incorporating the evolution of resistance in hosts can explain male-killer polymorphism. However, this is only likely if resistance genes are very costly. We also consider the long-term evolutionary dynamics of male-killers, and show that evolution towards progressively more 'efficient' male-killers can be thwarted by the appearance of host resistance. The presence of a resistance gene can allow a less efficient male-killer to outcompete its rival and hence reverse the trend towards more efficient transmission and reduced metabolic load on the host.