Data from: Differential effects of offspring and maternal inbreeding on egg laying and offspring performance in the burying beetle Nicrophorus vespilloides

We investigate the effect of offspring and maternal inbreeding on maternal and offspring traits associated with early offspring fitness in the burying beetle Nicrophorus vespilloides. We conducted two experiments. In the first experiment, we manipulated maternal inbreeding only (keeping offspring outbred) by generating mothers that were outbred, moderately inbred or highly inbred. Meanwhile, in the second experiment, we manipulated offspring inbreeding only (keeping females outbred) by generating offspring that were outbred, moderately inbred or highly inbred. In both experiments, we monitored subsequent effects on breeding success (number of larvae), maternal traits (clutch size, delay until laying, laying skew, laying spread and egg size) and offspring traits (hatching success, larval survival, duration of larval development, and average larval mass). Maternal inbreeding reduced breeding success, and this effect was mediated through lower hatching success and greater larval mortality. Furthermore, inbred mothers produced clutches where egg laying was less skewed towards the early part of laying than outbred females. This reduction in the skew in egg laying is beneficial for larval survival, suggesting that inbred females adjusted their laying patterns facultatively, thereby partially compensating for the detrimental effects of maternal inbreeding on offspring. Finally, we found evidence of a nonlinear effect of offspring inbreeding coefficient on number of larvae dispersing. Offspring inbreeding affected larval survival and larval development time but also unexpectedly affected maternal traits (clutch size and delay until laying), suggesting that females adjust clutch size and the delay until laying in response to being related to their mate.本研究以埋葬甲虫（Nicrophorus vespilloides）为实验对象，探究子代与母本近交对与子代早期适合度相关的母本及子代性状的影响。我们共开展两组对照实验：第一组实验仅操控母本近交水平（维持子代非近交），通过培育非近交、中度近交及高度近交的母本个体完成实验处理；与此同时，第二组实验仅操控子代近交水平（维持雌性交配亲本非近交），通过培育非近交、中度近交及高度近交的子代个体完成实验处理。两组实验中，我们均监测了后续相关指标的变化，涵盖繁殖成功率（以幼虫数量计）、母本性状（每窝产卵量、产卵延迟时长、产卵偏斜度、产卵跨度及卵尺寸），以及子代性状（孵化成功率、幼虫存活率、幼虫发育时长及平均幼虫体重）。研究结果显示，母本近交可降低繁殖成功率，该效应通过降低孵化成功率与提高幼虫死亡率得以实现。此外，相较于非近交雌虫，近交母本所产卵窝的产卵时间分布更不偏向于产卵初期；产卵偏斜度的降低对幼虫存活具有积极作用，这表明近交雌虫会通过适应性调整自身的产卵模式，从而部分抵消母本近交对子代产生的不利影响。最后，我们发现子代近交系数对扩散幼虫数量存在非线性影响的实验证据。子代近交不仅会影响幼虫存活率与幼虫发育时长，还会对母本性状（每窝产卵量与产卵延迟时长）产生意料之外的影响，这表明雌虫会根据自身与交配亲本的亲缘关系，适应性调整每窝产卵量及产卵延迟时长。