Data from: Intergenerational effects of inbreeding in Nicrophorus vespilloides: offspring suffer fitness costs when either they or their parents are inbred

Inbreeding depression is the reduction in fitness caused by mating between related individuals. Inbreeding is expected to cause a reduction in offspring fitness when the offspring themselves are inbred, but outbred individuals may also suffer a reduction in fitness when they depend on care from inbred parents. At present, little is known about the significance of such intergenerational effects of inbreeding. Here, we report two experiments on the burying beetle Nicrophorus vespilloides, an insect with elaborate parental care, in which we investigated inbreeding depression in offspring when either the offspring themselves or their parents were inbred. We found substantial inbreeding depression when offspring were inbred, including reductions in hatching success of inbred eggs and survival of inbred offspring. We also found substantial inbreeding depression when parents were inbred, including reductions in hatching success of eggs produced by inbred parents and survival of outbred offspring that received care from inbred parents. Our results suggest that intergenerational effects of inbreeding can have substantial fitness costs to offspring, and that future studies need to incorporate such costs to obtain accurate estimates of inbreeding depression.

近交衰退（inbreeding depression）指亲缘个体间交配所导致的适合度下降。当子代自身发生近交时，近交通常会引发子代适合度降低；但当远交个体依赖近交亲本的抚育时，其适合度也可能出现下降。目前，学界对近交的这类跨代效应的重要性尚缺乏充分认知。本研究以具有复杂抚育行为的埋葬甲（*Nicrophorus vespilloides*）为实验对象，开展了两项相关实验，分别设置子代自身近交以及亲本近交两种情境，探究子代的近交衰退情况。研究发现，子代自身近交时会出现显著的近交衰退，具体表现为近交卵的孵化成功率下降以及近交子代的存活率降低；同时亲本近交时同样存在显著的近交衰退，具体表现为近交亲本所产卵的孵化成功率下降，以及接受近交亲本抚育的远交子代的存活率降低。本研究结果表明，近交的跨代效应会对子代造成显著的适合度损失，未来相关研究需纳入这类效应带来的成本，才能对近交衰退做出准确的量化评估。