Data from: Experimental evolution reveals trade-offs between mating and immunity

Immune system maintenance and upregulation is costly. Sexual selection intensity, which increases male investment into reproductive traits, is expected to create trade-offs with immune function. We assayed phenoloxidase (PO) and lytic activity of individuals from populations of the Indian meal moth, Plodia interpunctella, which had been evolving under different intensities of sexual selection. We found significant divergence among populations, with males from female-biased populations having lower PO activity than males from balanced sex ratio or male-biased populations. There was no divergence in anti-bacterial lytic activity. Our data suggest that it is the increased male mating demands in female-biased populations that trades-off against immunity, and not the increased investment in sperm transfer per mating that characterizes male-biased populations.免疫系统的维持与上调均需付出高昂的进化成本。性选择强度可提升雄性对生殖性状的资源投入，预计其与免疫功能之间将存在进化权衡。我们以在不同性选择强度下演化的印度谷螟（*Plodia interpunctella*）种群个体为研究对象，测定了其酚氧化酶（phenoloxidase, PO）与溶菌活性（lytic activity）。研究发现不同种群间存在显著分化：雌性偏倚种群的雄性酚氧化酶活性，显著低于性比平衡或雄性偏倚种群的雄性。抗菌溶菌活性则未出现种群分化。本研究数据表明，雌性偏倚种群中雄性交配需求的提升，才是与免疫功能形成进化权衡的诱因，而非雄性偏倚种群所典型具备的单次交配精子转移投入增加。