Wilson Kenneth, Graham Robert I
Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK
Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK.
Biol Lett. 2015 Mar;11(3). doi: 10.1098/rsbl.2015.0012.
There is an increasing appreciation of the importance of transgenerational effects on offspring fitness, including in relation to immune function and disease resistance. Here, we assess the impact of parental rearing density on offspring resistance to viral challenge in an insect species expressing density-dependent prophylaxis (DDP); i.e. the adaptive increase in resistance or tolerance to pathogen infection in response to crowding. We quantified survival rates in larvae of the cotton leafworm (Spodoptera littoralis) from either gregarious- or solitary-reared parents following challenge with the baculovirus S. littoralis nucleopolyhedrovirus. Larvae from both the parental and offspring generations exhibited DDP, with gregarious-reared larvae having higher survival rates post-challenge than solitary-reared larvae. Within each of these categories, however, survival following infection was lower in those larvae from gregarious-reared parents than those from solitary-reared, consistent with a transgenerational cost of DDP immune upregulation. This observation demonstrates that crowding influences lepidopteran disease resistance over multiple generations, with potential implications for the dynamics of host-pathogen interactions.
跨代效应（包括对免疫功能和抗病性的影响）对后代适应性的重要性正日益受到重视。在此，我们评估了亲代饲养密度对一种具有密度依赖性预防作用（DDP）的昆虫物种后代抗病毒攻击能力的影响；即，昆虫对病原体感染的抗性或耐受性会随着拥挤程度而适应性增加。我们对棉铃虫（Spodoptera littoralis）幼虫的存活率进行了量化，这些幼虫的亲代分别是群居饲养或单独饲养的，之后用杆状病毒——棉铃虫核多角体病毒对它们进行攻击。亲代和子代幼虫均表现出密度依赖性预防作用，群居饲养的幼虫在受到攻击后的存活率高于单独饲养的幼虫。然而，在每一类中，群居饲养的亲代所产幼虫在感染后的存活率低于单独饲养的亲代所产幼虫，这与密度依赖性预防作用免疫上调的跨代成本一致。这一观察结果表明，拥挤对鳞翅目昆虫抗病性的影响会持续多代，这对宿主 - 病原体相互作用的动态变化可能具有重要意义。
