Coevolution between Tribolium Castaneum and Bacillus Thuringiensis: On the Evolutionary Significance of Genetic Specificity and Specific Immunity. CLUSTER: "Experimental Evolution and Natural Variation of Bacillus-Invertebrate Interactions"

宿主-寄生虫协同进化严重依赖于遗传特异性，这将促进相互作用的宿主和寄生虫的相互遗传变化。另一方面，当诱导的免疫应答显示出对某种寄生虫类型的特异性时，特异性也可以以表型可塑性的形式出现。我们可以预期，这种表型灵活性的优势降低了宿主和寄生虫遗传变化的速度，这意味着它可能会减缓红皇后的动态。这一建议涉及两种形式的特异性及其与宿主-寄生虫共同进化的相关性。我们特别讨论这种特异性如何演变的问题。实验宿主-寄生虫之间的共同进化赤拟谷盗和其微寄生虫苏云金芽孢杆菌将用于测试是否共同进化创造遗传特异性。另一方面，我们将使用选择实验来测试免疫系统是否可以进化到更高或更低的能力，以应对诱导的特异性反应。结合这些方法，我们将最终研究诱导免疫影响宿主-寄生虫共同进化速度的程度。重要的是，这一优先方案将使我们能够直接研究宿主-寄生虫共同进化过程中特异性免疫和遗传变化的遗传原因。

Host-parasite coevolution critically relies on genetic specificity, which will facilitate reciprocal genetic change in interacting hosts and parasites. On the other hand, specificity can also come in a phenotypically plastic form, when induced immune responses show specificity for a certain parasite type. We may expect that a preponderance of such phenotypic flexibility reduces the speed with which hosts and parasites change genetically, which means that it might slow down Red Queen dynamics. This proposal addresses both forms of specificity and their relevance for host-parasite coevolution. We particularly address the question how such specificity evolves. Experimental host-parasite coevolution between the red flour beetle Tribolium castaneum and its microparasite Bacillus thuringiensis will serve to test whether coevolution creates genetic specificity. On the other hand, we will use selection experiments to test whether the immune system can evolve towards higher or lower capacity to respond with induced, specific responses. Combining these approaches, we will finally study the degree to which induced immunity influences the speed of host-parasite coevolution. Importantly, this priority programme will enable us to directly study the genetic causes of both specific immunity and the genetic changes during host-parasite coevolution.