Paietta J, Sargent M L
Proc Natl Acad Sci U S A. 1981 Sep;78(9):5573-7. doi: 10.1073/pnas.78.9.5573.
The effect of flavin deficiency on blue light responses in Neurospora crassa was studied through the use of two riboflavin mutants (rib-1 and rib-2). The photoresponses assayed were the suppression of circadian conidiation, the phase shifting of the circadian conidiation rhythm, and the induction of carotenoid synthesis. Flavin deficiency was induced in the rib-1 mutant by restrictive growth temperatures and in the rib-2 mutant by low levels of supplemental riboflavin. At 26 degrees C, a semirestrictive growth temperature, the rib-1 mutant is about 1/80th as sensitive to light for the photosuppression of circadian conidiation. Flavin deficiency in the rib-1 and rib-2 strains was effective in reducing the photosensitivity for phase shifting and carotenogenesis to about 1/16th and 1/4th of normal, respectively. Experiments with permissive temperatures, riboflavin supplementation, and revertants at the rib locus all indicated that the effects on light sensitivity were due solely to the presence of the rib mutations. These results provide evidence that one or more flavin photoreceptors are involved in the blue light responses of Neurospora.
通过使用两种核黄素突变体（rib-1和rib-2），研究了核黄素缺乏对粗糙脉孢菌蓝光反应的影响。所测定的光反应包括昼夜分生孢子形成的抑制、昼夜分生孢子形成节律的相移以及类胡萝卜素合成的诱导。通过限制生长温度在rib-1突变体中诱导核黄素缺乏，通过低水平补充核黄素在rib-2突变体中诱导核黄素缺乏。在26℃（半限制生长温度）下，rib-1突变体对昼夜分生孢子形成的光抑制的光敏感性约为正常的1/80。rib-1和rib-2菌株中的核黄素缺乏分别有效地将相移和类胡萝卜素生成的光敏感性降低到正常的约1/16和1/4。在允许温度、补充核黄素以及rib位点回复突变体的实验均表明，对光敏感性的影响完全是由于rib突变的存在。这些结果提供了证据，表明一种或多种核黄素光感受器参与了粗糙脉孢菌的蓝光反应。
