Carter A W, Durant S E, Hepp G R, Hopkins W A
Department of Fish and Wildlife Conservation, Blacksburg, Virginia 24061, USA.
J Exp Zool A Ecol Genet Physiol. 2013 Aug;319(7):422-9. doi: 10.1002/jez.1805. Epub 2013 Jun 17.
Environmental conditions during early development can profoundly influence an individual's phenotype. Development requires simultaneous maturation and orchestration of multiple physiological systems creating the potential for interaction among key systems and requiring substantial resources. We investigated the influence of thermoregulation on immunocompetence in Wood Duck ducklings (Aix sponsa). At both 1 and 2 days post hatch (dph) we evaluated ducklings' abilities to thermoregulate during a thermal challenge at one of four temperatures (36 [thermoneutral controls], 20, 10, or 5°C). At 3 dph, ducklings received a superficial wound, which was monitored until full recovery to quantify wound healing ability, an ecologically relevant, integrative measure of immune function. We demonstrated that duckling body temperature decreased with increasing thermal challenge severity, thermoregulatory ability increased with age, and thermoregulation had temperature-dependent effects on the immune system. Specifically, a more severe thermal challenge (5°C) resulted in decreased immune performance when compared to a mild challenge (20°C). We conclude that early thermoregulatory experiences are influential in shaping immune responses early in development. Furthermore, our results emphasize that future studies of environmental stressors need to consider multiple physiological endpoints since interaction among systems can result in competing physiological demands.
早期发育期间的环境条件会深刻影响个体的表型。发育需要多个生理系统同时成熟并协调运作，这就为关键系统之间的相互作用创造了可能性，并且需要大量资源。我们研究了温度调节对林鸳鸯雏鸭（Aix sponsa）免疫能力的影响。在孵化后1天和2天（dph），我们评估了雏鸭在四种温度（36℃[热中性对照]、20℃、10℃或5℃）之一的热应激期间的温度调节能力。在3 dph时，雏鸭接受了一个浅表伤口，对其进行监测直至完全恢复，以量化伤口愈合能力，这是一种与生态相关的免疫功能综合指标。我们证明，雏鸭体温随着热应激严重程度的增加而降低，温度调节能力随年龄增长而提高，并且温度调节对免疫系统有温度依赖性影响。具体而言，与轻度热应激（20℃）相比，更严重的热应激（5℃）导致免疫性能下降。我们得出结论，早期的温度调节经历对发育早期免疫反应的形成有影响。此外，我们的结果强调，未来对环境应激源的研究需要考虑多个生理终点，因为系统之间的相互作用可能导致相互竞争的生理需求。
