When sensing is gambling: an experimental system reveals how plasticity can generate tunable bet-hedging strategies

Genotypes can persist in unpredictable environments by ‘hedging their bets’ and producing diverse phenotypes. Theoretical studies have shown that the phenotypic variability needed for a bet-hedging strategy can be generated by factors either inside or outside an organism. However, sensing the environment and bet hedging are frequently treated as distinct evolutionary strategies. Furthermore, nearly all empirical studies of the molecular underpinnings of bet-hedging strategies to date have focused on internal sources of variability. We took a synthetic approach and constructed an experimental system where a phenotypic trade-off is mediated by actively sensing a cue present in the environment. We show that active sensing can generate a diversified bet-hedging strategy. Mutations affecting the norm of reaction to the cue alter the diversification strategy, indicating that bet hedging by active sensing is evolvable. Our results indicate that a broader class of biological systems should be c...

基因型可通过“两头下注（bet-hedging）”策略生成多样化表型，从而在不可预测的环境中得以存续。理论研究表明，实施两头下注策略所需的表型变异，可由生物体内部或外部的因素诱发产生。然而，环境感知与两头下注策略常被视为两类独立的进化策略。此外，迄今为止，所有针对两头下注策略分子基础的实证研究，几乎都聚焦于变异的内部来源。本研究采用合成生物学方法，构建了一套实验系统：在该系统中，表型权衡（phenotypic trade-off）由对环境中存在的信号的主动感知所介导。本研究证实，主动感知可催生多样化的两头下注策略。影响对该信号的反应规范（norm of reaction）的突变，会改变该多样化策略，这表明通过主动感知实现的两头下注策略是可演化的。本研究结果表明，更广泛的一类生物系统应被……