Circadian rhythms in Neurospora crassa:: Farnesol or geraniol allow expression of rhythmicity in the otherwise arrhythmic strains frq10, wc-1, and wc-2
Circadian rhythms in Neurospora crassa:: Farnesol or geraniol allow expression of rhythmicity in the otherwise arrhythmic strains frq10, wc-1, and wc-2
复制标题
DOI：
10.1177/0748730403255934
复制
发表时间：
2003-08-01
影响因子：
3.5
通讯作者：
Brody, S
中科院分区：
文献类型：
--
作者：
Granshaw, T;Tsukamoto, M;Brody, S
在粗糙脉孢菌中，可以在bd（带）菌株中看到昼夜节律，其为琼脂培养基表面上的一系列“带”或分生孢子（孢子形成）区域。3个不同基因（frq、wc-1或wc-2）的某些突变导致昼夜节律的丧失。在这项研究中，发现添加10（-4）至10（-5）M的香叶醇或法尼醇恢复了由于这3个基因中的任何一个突变而缺乏昼夜节律的菌株的节律带。这3个条件性抑制菌株现在表现出强大的，自由运行的conicliation节奏。它们的节律既不是温度补偿的，也不是对光明显敏感的，所以昼夜节律的全部特性没有恢复。在20 ℃下，在生长管中，法尼醇处理分别为frq（10），wc-1和wc-2菌株提供了28，26和22小时的时间。20 ℃下香叶醇处理frq（10）、wc-1和wc-2菌株的时间分别为23、25.5和24.5 h。在香叶醇存在下生长的frq（10）菌株的温度脉冲（1小时，20至40 ℃）的PRC显示出强重置（0型），表明存在温度敏感振荡器。法尼醇和香叶醇与类固醇（或甲羟戊酸）途径中的已知中间体有关。这些数据被解释在一个2-振荡器模型，其中法尼醇/香叶醇激活或放大剩余的振荡器（一个假定的无frq振荡器）。
In Neurospora crassa, the circadian rhythm can be seen in the bd (band) strain as a series of "bands" or conidiation (spore-forming) regions on the surface of an agar medium. Certain mutations at 3 different genes (frq, wc-1, or wc-2) lead to the loss of the circadian rhythm. In this study, it was found that the addition of 10(-4) to 10(-5) M of geraniol or farnesol restored rhythmic banding to strains that lack a circadian rhythm due to mutations in any I of these 3 genes. These 3 conditionally arrhythmic strains now exhibited robust, free-running conicliation rhythms. Their rhythms were neither temperature-compensated nor obviously sensitive to light, so the full properties of a circadian rhythm were not restored. At 20 degreesC, in growth tubes, farnesol treatment gave periods of 28, 26, and 22 h for the frq(10), wc-1, and wc-2 strains, respectively. Geraniol treatment at 20 degreesC gave periods of 23, 25.5, and 24.5 h for the frq(10), wc-1, and wc-2 strains, respectively. A PRC for temperature pulses (1 h, 20 to 40 degreesC) for the frq(10) strain grown in the presence of geraniol showed strong resetting (type 0), suggesting that a temperature-sensitive oscillator was present. Farnesol and geraniol are related to known intermediates in the steroid (or mevalonate) pathway. These data are interpreted in terms of a 2-oscillator model, in which farnesol/geraniol activate or amplify a remaining oscillator (a postulated frq-less oscillator).