Flôres Danilo E F L, Jannetti Milene G, Improta Giovane C, Tachinardi Patricia, Valentinuzzi Veronica S, Oda Gisele A
Laboratorio de Cronobiologia Binacional Argentina-Brasil, Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil.
Laboratorio de Cronobiologia Binacional Argentina-Brasil, Centro Regional de Investigaciones Cientificas y de Transferencia Tecnológica (CRILAR), Anillaco, Argentina.
Front Physiol. 2021 Oct 1;12:738471. doi: 10.3389/fphys.2021.738471. eCollection 2021.
Living organisms anticipate the seasons by tracking the proportion of light and darkness hours within a day-photoperiod. The limits of photoperiod measurement can be investigated in the subterranean rodents tuco-tucos ( aff. ), which inhabit dark underground tunnels. Their exposure to light is sporadic and, remarkably, results from their own behavior of surface emergence. Thus, we investigated the endogenous and exogenous regulation of this behavior and its consequences to photoperiod measurement. In the field, animals carrying biologgers displayed seasonal patterns of daily surface emergence, exogenously modulated by temperature. In the laboratory, experiments with constant lighting conditions revealed the endogenous regulation of seasonal activity by the circadian clock, which has a multi-oscillatory structure. Finally, mathematical modeling corroborated that tuco-tuco's light exposure across the seasons is sufficient for photoperiod encoding. Together, our results elucidate the interrelationship between the circadian clock and temperature in shaping seasonal light exposure patterns that convey photoperiod information in an extreme photic environment.
生物通过追踪一天内光照和黑暗时间的比例——光周期来预测季节。可以在生活在黑暗地下隧道中的地下啮齿动物土库土鼠（近缘种）身上研究光周期测量的极限。它们对光的暴露是零星的，而且值得注意的是，这是由它们自己的地表出现行为导致的。因此，我们研究了这种行为的内源性和外源性调节及其对光周期测量的影响。在野外，携带生物记录器的动物表现出每日地表出现的季节性模式，这种模式受到温度的外源性调节。在实验室中，在恒定光照条件下进行的实验揭示了昼夜节律时钟对季节性活动的内源性调节，昼夜节律时钟具有多振荡结构。最后，数学模型证实，土库土鼠全年的光照暴露足以进行光周期编码。总之，我们的结果阐明了昼夜节律时钟和温度在塑造季节性光照暴露模式中的相互关系，这些模式在极端光照环境中传递光周期信息。
