Roth Olivia, Landis Susanne H
GEOMAR Evolutionary Ecology of Marine Fishes Helmholtz Centre for Ocean Research Kiel Germany.
Evol Appl. 2017 Apr 14;10(5):514-528. doi: 10.1111/eva.12473. eCollection 2017 Jun.
Trans-generational plasticity (TGP) is the adjustment of phenotypes to changing habitat conditions that persist longer than the individual lifetime. Fitness benefits (adaptive TGP) are expected upon matching parent-offspring environments. In a global change scenario, several performance-related environmental factors are changing simultaneously. This lowers the predictability of offspring environmental conditions, potentially hampering the benefits of TGP. For the first time, we here explore how the combination of an abiotic and a biotic environmental factor in the parental generation plays out as trans-generational effect in the offspring. We fully reciprocally exposed the parental generation of the pipefish to an immune challenge and elevated temperatures simulating a naturally occurring heatwave. Upon mating and male pregnancy, offspring were kept in ambient or elevated temperature regimes combined with a heat-killed bacterial epitope treatment. Differential gene expression (immune genes and DNA- and histone-modification genes) suggests that the combined change of an abiotic and a biotic factor in the parental generation had interactive effects on offspring performance, the temperature effect dominated over the immune challenge impact. The benefits of certain parental environmental conditions on offspring performance did not sum up when abiotic and biotic factors were changed simultaneously supporting that available resources that can be allocated to phenotypic trans-generational effects are limited. Temperature is the master regulator of trans-generational phenotypic plasticity, which potentially implies a conflict in the allocation of resources towards several environmental factors. This asks for a reassessment of TGP as a short-term option to buffer environmental variation in the light of climate change.
跨代可塑性（TGP）是指表型根据变化的栖息地条件进行调整，且这种调整持续时间长于个体寿命。当亲子环境匹配时，预计会产生适应性益处（适应性TGP）。在全球变化的情景下，几个与性能相关的环境因素同时发生变化。这降低了后代环境条件的可预测性，可能会阻碍TGP的益处。我们首次在此探讨亲代中一个非生物环境因素和一个生物环境因素的组合如何作为跨代效应在后代中显现。我们将海龙的亲代完全相互暴露于免疫挑战和模拟自然发生的热浪的高温环境中。在交配和雄性怀孕后，将后代置于环境温度或高温环境中，并结合热灭活细菌表位处理。差异基因表达（免疫基因以及DNA和组蛋白修饰基因）表明，亲代中一个非生物因素和一个生物因素的联合变化对后代性能具有交互作用，温度效应超过了免疫挑战的影响。当非生物因素和生物因素同时改变时，某些亲代环境条件对后代性能的益处并未累加，这支持了可分配给表型跨代效应的可用资源是有限的这一观点。温度是跨代表型可塑性的主要调节因子，这可能意味着在向多个环境因素分配资源方面存在冲突。鉴于气候变化，这就需要重新评估TGP作为缓冲环境变化的短期选择。
