Data from: Different effects of paternal trans-generational immune priming on survival and immunity in step and genetic offspring

Paternal trans-generational immune priming, whereby fathers provide immune protection to offspring, has been demonstrated in the red flour beetle Tribolium castaneum exposed to the insect pathogen Bacillus thuringiensis. However, it is currently unclear how such protection is transferred, since in contrast to mothers, fathers do not directly provide offspring with a large amount of substances. In addition to sperm, male flour beetles transfer seminal fluids to females during copulation. Depending on whether paternal trans-generational immune priming is mediated by sperm or seminal fluids, it is expected to either affect only the genetic offspring of a male, or also their half-sibs that are sired by another male. We therefore conducted a double-mating experiment and found that only the genetic offspring of an immune primed male show enhanced survival upon bacterial challenge, while phenoloxidase activity, an important insect immune trait, and the expression of the immune receptor PGRP-LC were increased in all offspring. This indicates that information leading to enhanced survival upon pathogen exposure is transferred via sperm, and thus potentially constitute an epigenetic effect, whereas substances transferred with the seminal fluid could have an additional influence on offspring immune traits.

父系跨代免疫致敏（Paternal trans-generational immune priming）指父本为子代提供免疫保护的现象，该现象已在暴露于昆虫病原苏云金芽孢杆菌（Bacillus thuringiensis）的赤拟谷盗（Tribolium castaneum）中得到验证。但目前学界尚未明确此类免疫保护的传递机制：与母本不同，父本无法直接为子代提供大量相关物质。除精子外，雄性赤拟谷盗在交配过程中还会向雌性交配个体传递精液（seminal fluids）。根据父系跨代免疫致敏的介导因子为精子或精液的不同情形，该效应要么仅影响父本的遗传子代，要么也会波及由其他雄性父本所产生的同父异母子代。为此我们开展了双交配实验，结果显示：仅免疫致敏父本的遗传子代在受到细菌攻毒后存活率显著提升；而所有子代的重要昆虫免疫性状——酚氧化酶（phenoloxidase）活性，以及免疫受体PGRP-LC的表达水平均有所升高。上述结果表明，可提升病原体暴露后存活率的相关信息是通过精子传递的，这可能属于一种表观遗传效应（epigenetic effect）；而随精液传递的物质则可能对子代的免疫性状产生额外影响。