Vaz Nunes M
Department of Biology, Imperial College at Silwood Park, Ascot, Berkshire, United Kingdom.
J Biol Rhythms. 1998 Dec;13(6):461-70. doi: 10.1177/074873098129000291.
The "double circadian oscillator model" for the photoperiodic clock has been used to simulate thermoperiodic responses in insects and mites. Two assumptions have been made: (1) the clock measures cryophase in a similar way to scotophase, and (2) temperature cycles are able to entrain the clock in a similar way to LD cycles. Simulations showed that Assumption 1 causes the "critical cryophase" to be of about equal duration as the critical night length. Assumption 2 is not always needed if diapause incidences in DD are high at low temperatures but low or zero at high temperatures. The latter assumption is needed, however, if high diapause occurs in thermoperiodic cycles in DD, whereas nondiapause occurs in DD with both high and low constant temperatures. The model accounts for the observation that the amplitude of the temperature cycle is important in some insects, whereas the temperature of the cryophase is crucial in others.
用于光周期时钟的“双昼夜振荡器模型”已被用于模拟昆虫和螨类的热周期反应。已经做出了两个假设：（1）时钟测量低温期的方式与测量暗期的方式类似，（2）温度循环能够以与光暗循环类似的方式使时钟同步。模拟结果表明，假设1导致“临界低温期”的持续时间与临界夜长大致相等。如果在低温下DD中的滞育发生率高而在高温下低或为零，则假设2并非总是必需的。然而，如果在DD的热周期中发生高滞育，而在高温和低温恒定的DD中发生非滞育，则需要后一个假设。该模型解释了这样的观察结果：温度循环的幅度在某些昆虫中很重要，而低温期的温度在其他昆虫中至关重要。
