Organisms possess photoperiodic timing mechanisms to detect variations in day length and temperature as the seasons progress. The nature of the molecular mechanisms interpreting and signaling these environmental changes to elicit downstream neuroendocrine and physiological responses are just starting to emerge. Here, we demonstrate that, in Drosophila melanogaster, EYES ABSENT (EYA) acts as a seasonal sensor by interpreting photoperiodic and temperature changes to trigger appropriate physiological responses. We observed that tissue-specific genetic manipulation of eya expression is sufficient to disrupt the ability of flies to sense seasonal cues, thereby altering the extent of female reproductive dormancy. Specifically, we observed that EYA proteins, which peak at night in short photoperiod and accumulate at higher levels in the cold, promote reproductive dormancy in female D. melanogaster. Furthermore, we provide evidence indicating that the role of EYA in photoperiodism and temperature sensing is aided by the stabilizing action of the light-sensitive circadian clock protein TIMELESS (TIM). We postulate that increased stability and level of TIM at night under short photoperiod together with the production of cold-induced and light-insensitive TIM isoforms facilitate EYA accumulation in winter conditions. This is supported by our observations that tim null mutants exhibit reduced incidence of reproductive dormancy in simulated winter conditions, while flies overexpressing tim show an increased incidence of reproductive dormancy even in long photoperiod.

有机体具有光周期定时机制，可以检测季节变化过程中日长和温度的变化。解释和信号传导这些环境变化以引起下游神经内分泌和生理反应的分子机制的性质才刚刚开始出现。在这里，我们证明，在果蝇中，EYES ABSENT（EYA）通过解释光周期和温度变化以触发适当的生理反应而充当季节传感器。我们观察到eya的组织特异性基因操作表达足以破坏果蝇感知季节信号的能力，从而改变雌性生殖休眠的程度。具体而言，我们观察到EYA蛋白促进了雌性D. melanogaster的生殖休眠，该蛋白在短的光周期在夜间达到峰值，并在寒冷的环境中以较高的水平积累。此外，我们提供的证据表明EYA在光周期和温度感测中的作用是受光敏生物钟时钟蛋白TIMELESS（TIM）的稳定作用的辅助。我们推测，短期内在短期光周期下提高TIM的稳定性和水平，以及产生冷诱导和对光不敏感的TIM亚型有助于冬季EYA的积累。这是通过我们的观察结果支持恬空的突变体在模拟的冬季条件下生殖休眠的发生率降低，而过表达TIM的果蝇即使在长时间的光周期下也表现出生殖休眠的发生率增加。