Goto Shin G, Numata Hideharu
Department of Biology and Geosciences, Graduate School of Science, Osaka City University, Osaka 558-8585, Japan.
J Insect Physiol. 2009 May;55(5):401-7. doi: 10.1016/j.jinsphys.2008.11.008. Epub 2008 Dec 25.
Physiological characteristics of the photoreceptors involved in the photoperiodic induction of diapause were investigated in the flesh fly Sarcophaga similis. Both the early and late phases of scotophase were sensitive to light and a light pulse during each of these phases prevented diapause. Certain physiological differences between the phases were, nevertheless, detected. Compared with early scotophase, late scotophase required a light pulse with a long period and a large number of night interruption photoperiodic cycles in order to effectively prevent diapause. The diapause-averting effects of a light pulse during early scotophase were canceled by an additional long dark period, but those during late scotophase were not. Thus, the diapause-averting effects produced during early scotophase are different to those produced during late scotophase. The early scotophase was sensitive to light at wavelengths of 470nm or shorter, but not to light of 583nm or longer. In contrast, the late scotophase was sensitive to light of a broad range of wavelengths, ranging from 395 to 660nm. Furthermore, the early scotophase was considerably more sensitive to monochromatic light with low photon flux density than the late scotophase. These results suggest that different types of photoreceptor are involved in the photoperiodic response.
在肉蝇相似尸蝇中研究了参与滞育光周期诱导的光感受器的生理特性。暗期的早期和晚期对光均敏感，在这两个阶段中的任何一个阶段给予光脉冲都可阻止滞育。然而，仍检测到这两个阶段之间存在某些生理差异。与暗期早期相比，暗期晚期需要较长时间的光脉冲和大量的夜间中断光周期循环才能有效阻止滞育。暗期早期的光脉冲的滞育避免效应会被额外的长黑暗期抵消，但暗期晚期的则不会。因此，暗期早期产生的滞育避免效应与暗期晚期产生的不同。暗期早期对波长为470nm或更短的光敏感，但对波长为583nm或更长的光不敏感。相比之下，暗期晚期对波长范围从395至660nm的光敏感。此外，暗期早期对低光子通量密度的单色光比暗期晚期敏感得多。这些结果表明，不同类型的光感受器参与了光周期反应。
