Data from: Genotype-specific interactions between parasitic arthropods

Despite the ubiquity of coinfection, we know little of the effects of intra-specific genetic variability on coinfection by distinct parasite species. Here we test the hypothesis that parasite multiplication depends on the combination of parasite genotypes that coinfect the host (that is Genotype.parasite × Genotype.parasite interaction). To that aim, we infected tomato leaves with the ecto-parasitic mites Tetranychus urticae and Tetranychus evansi. We tested all possible combinations between four T. urticae and two T. evansi populations sampled on different hosts or localities. There was no universal (that is genotype-independent) effect of coinfection on mite multiplication; in many cases the two species had no effect on each other. However, several combinations of T. evansi and T. urticae populations led to elevated T. evansi numbers. Similarly, T. urticae reproduction largely depended on the interaction between T. urticae and T. evansi populations. This evidence for genotype-by-genotype interaction between coinfecting parasites indicates that the effect of coinfection on parasite epidemiology and evolution may vary in space according to the genetic composition of local parasite populations; it further suggests the possibility of coevolution between parasites species that share the same hosts.尽管共感染现象普遍存在，但目前学界对种内遗传变异如何影响不同寄生虫物种的共感染过程仍缺乏深入认知。本研究旨在验证下述假说：寄生虫的增殖水平取决于共感染宿主的寄生虫基因型组合，即寄生虫基因型×寄生虫基因型互作。为此，我们以番茄叶片为宿主，接种了两种外寄生叶螨：二斑叶螨（Tetranychus urticae）与截形叶螨（Tetranychus evansi）。我们选取了分别采自不同宿主或地理区域的4个二斑叶螨种群与2个截形叶螨种群，测试了二者所有可能的种群组合。研究发现，共感染对叶螨增殖的影响并不存在普适性（即不依赖于基因型）的模式：在多数组合中，两种叶螨彼此之间并未产生显著影响。但在部分种群组合中，截形叶螨的种群数量出现了显著提升。同理，二斑叶螨的繁殖能力也很大程度上依赖于二者的种群互作效应。上述共感染寄生虫间存在基因型×基因型互作的实验证据表明，共感染对寄生虫流行病学与进化动态的影响，可能会因当地寄生虫种群的遗传组成不同而存在空间异质性；该结果同时提示，共享同一宿主的不同寄生虫物种之间存在协同进化的可能性。