Data from: Ecdysteroid hormones link the juvenile environment to alternative adult life histories in a seasonal insect

The conditional expression of alternative life strategies is a widespread
feature of animal life and a pivotal adaptation to life in seasonal
environments. To optimally match suites of traits to seasonally changing
ecological opportunities, animals living in seasonal environments need
mechanisms linking information on environmental quality to resource
allocation decisions. The butterfly Bicyclus anynana expresses alternative
adult life histories in the alternating wet and dry seasons of its habitat
as endpoints of divergent developmental pathways triggered by seasonal
variation in preadult temperature. Pupal ecdysteroid hormone titers are
correlated with the seasonal environment, but whether they play a
functional role in coordinating the coupling of adult traits in the
alternative life histories is unknown. Here, we show that manipulating
pupal ecdysteroid levels is sufficient to mimic in direction and magnitude
the shifts in adult reproductive resource allocation normally induced by
seasonal temperature. Crucially, this allocation shift is accompanied by
changes in ecologically relevant traits, including timing of reproduction,
life span, and starvation resistance. Together, our results support a
functional role for ecdysteroids during development in mediating strategic
reproductive investment decisions in response to predictive indicators of
environmental quality. This study provides a physiological mechanism for
adaptive developmental plasticity, allowing organisms to cope with
variable environments.

替代生活策略的条件性表达是动物生命活动的普遍特征，也是适应季节性环境的关键适应性特征。为使性状组合与季节性变化的生态机遇实现最优匹配，栖息于季节性环境中的动物需要具备将环境质量信息与资源分配决策相关联的调控机制。矍眼蝶（Bicyclus anynana）会在其栖息地的干湿交替季中展现出差异化的成虫生活史类型，这些生活史是由预成虫期温度的季节性变化所触发的分化发育通路的最终结果。蛹蜕皮激素（ecdysteroid）滴度与季节性环境存在相关性，但目前尚不明确其是否在协调替代生活史中成虫性状的耦合关系中发挥功能性作用。本研究证实，操纵蛹蜕皮激素水平，足以在变化方向与幅度上模拟由季节性温度常规诱导的成虫繁殖资源分配转变。尤为关键的是，这种资源分配转变同时伴随有与生态适应性相关的性状改变，包括繁殖时机、寿命以及抗饥饿能力。综合来看，我们的研究结果支持蜕皮激素在发育过程中可介导针对环境质量预测指标的战略性繁殖投入决策，发挥功能性调控作用。本研究为适应性发育可塑性提供了一种生理学机制，助力生物应对多变的环境。