Mating promotes reproductive activity, which may impact immune performance. Paradoxically, mating frequently challenges females' immunity (e.g., infections). Therefore, studies of postmating resource allocation between reproduction and survival are likely to shed new light on life-history trade-off and sexual selection. Here, we used RNAseq to test whether and how mating affected mRNA expression in genes related to reproduction and immunity in Spodoptera litura female moths. Results show a divergent change in the differentially expressed genes (DEGs) between reproduction and immunity: the immune response was largely downregulated shortly after mating (~6 h postmating), which has some recovery at 24 h postmating; reproductive response is trivial shortly after mating (~6 h postmating), but it largely upregulated at 24 h postmating (e.g., egg maturation related genes were highly upregulated). Considering the fact that most of the total DEGs downregulated from 0 to 6 h postmating (from 51/68 to 214/260) but most of the total DEGs upregulated at 24 h postmating (816/928), it is possible that trade-offs between reproduction and immunity occurred in mated females. For example, they may shut down immunity to favor sperm storage and save limited resources to support the increased energy required in reproduction (e.g., egg maturation and oviposition). Mating-induced infections should be trivial due to low polyandry in S. litura. A reduced immune defense may have no threat to S. litura survival but may benefit reproduction significantly. Furthermore, obvious expression changes were detected in genes related to hormone production, suggesting that endocrine changes could play important roles in postmating responses.

中文翻译：

---

斜纹夜蛾（鳞翅目：夜蛾科）雌蛾中交配诱导的与繁殖和免疫相关的基因的差异表达。

交配促进生殖活动，这可能会影响免疫性能。矛盾的是，交配经常挑战雌性的免疫力（例如感染）。因此，关于繁殖和生存之间交配后资源分配的研究可能会为生活史权衡和性选择提供新的线索。在这里，我们使用 RNAseq 来测试交配是否以及如何影响斜纹夜蛾雌蛾中与繁殖和免疫相关的基因的 mRNA 表达。结果显示，生殖和免疫之间的差异表达基因（DEG）存在不同的变化：交配后不久（交配后约6小时）免疫反应大幅下调，交配后24小时有一定程度的恢复；交配后不久（〜交配后6小时），生殖反应微不足道，但在交配后24小时大幅上调（例如，卵子成熟相关基因高度上调）。考虑到大多数 DEG 总量从交配后 0 小时到 6 小时下调（从 51/68 到 214/260），但大多数 DEG 总量在交配后 24 小时上调（816/928），因此可能需要权衡生殖和免疫之间发生在交配的雌性中。例如，它们可能会关闭免疫力以利于精子储存并节省有限的资源以支持繁殖（例如卵子成熟和产卵）所需的增加的能量。由于斜纹夜蛾一妻多夫的程度较低，交配引起的感染应该是微不足道的。免疫防御的降低可能对斜纹夜蛾的生存没有威胁，但可能显着有利于繁殖。此外，在与激素产生相关的基因中检测到明显的表达变化，表明内分泌变化可能在交配后反应中发挥重要作用。