Data from: Does multiple paternity influence offspring disease-resistance?

It has been suggested that polyandry allows females to increase offspring genetic diversity and reduce the prevalence and susceptibility of their offspring to infectious diseases. We tested this hypothesis in wild-derived house mice (Mus musculus) by experimentally infecting the offspring from 15 single- and 15 multiple-sired litters with two different strains of a mouse pathogen (Salmonella Typhimurium) and compared their ability to control infection. We found a high variation in individual infection resistance (measured with pathogen loads) and significant differences among families, suggesting genetic effects on Salmonella resistance, but we found no difference in prevalence or infection resistance between single- vs. multiple-sired litters. We found a significant sex difference in infection resistance, but surprisingly, males were more resistant to infection than females. Also, infection resistance was correlated with weight loss during infection, although only for females, indicating that susceptibility to infection had more harmful health consequences for females than for males. To our knowledge, our findings provide the first evidence for sex-dependent resistance to Salmonella infection in house mice. Our results do not support the hypothesis that multiple-sired litters are more likely to survive infection than single-sired litters; however, as we explain, additional studies are required before ruling out this hypothesis.已有研究提出，一妻多夫制（polyandry）可使雌性提升后代的遗传多样性，并降低后代感染传染病的概率与易感性。我们以野生起源的家鼠（Mus musculus）为实验对象，针对15胎单父系后代与15胎多父系后代，分别接种两种不同毒株的鼠伤寒沙门氏菌（Salmonella Typhimurium），以此验证该假说，并比较两组后代的感染控制能力。研究发现，个体间的感染抗性（以病原体载量衡量）存在较高变异，且不同家系间存在显著差异，这表明感染抗性存在遗传效应；但我们未发现单父系与多父系后代在感染率或感染抗性上存在显著差异。我们还观察到感染抗性存在显著的性别差异，然而出乎意料的是，雄性的感染抗性强于雌性。此外，感染抗性与感染期间的体重下降存在相关性，但该相关性仅存在于雌性个体中，这提示感染易感性对雌性的健康危害更甚于雄性。据我们所知，本研究首次在家鼠中发现了针对鼠伤寒沙门氏菌感染的性别依赖性抗性。我们的结果不支持“多父系后代比单父系后代更易在感染中存活”的假说；但正如我们所阐释的，在排除该假说前仍需开展更多相关研究。