Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Sevilla, Spain.
Genetics. 2010 Mar;184(3):651-8. doi: 10.1534/genetics.109.109975. Epub 2009 Dec 21.
The development of asexual spores, that is, the process of conidiation, in the fungus Neurospora crassa is increased by light. The fluffy (fl) gene, encoding a major regulator of conidiation, is activated by light. We describe here a detailed characterization of the regulation by blue light of fl in vegetative hyphae. This induction requires the white collar complex (WCC) while the FLD protein acts as a dark repressor of fl transcription. We show that the WCC directly regulates fl transcription in response to blue light after transiently binding the promoter. We propose that fl is repressed by FLD in vegetative mycelia and that the repression is lost after light exposure and WCC activation. The increase in fl mRNA in vegetative mycelia after light exposure, and the corresponding increase in the amount of the regulatory FL protein, should promote the activation of the conidiation pathway. The activation by light of fl provides a simple mechanism for the activation of conidiation by blue light in Neurospora that may be at work in other fungi.
无性孢子的发育，也就是分生孢子形成的过程，在粗糙脉孢菌中会受到光照的促进。编码分生孢子形成主要调控因子的 fluffy (fl) 基因会被光照激活。我们在这里详细描述了蓝光照对 fl 在营养菌丝中的调控。这种诱导需要白冠复合物（WCC），而 FLD 蛋白则作为 fl 转录的暗阻遏物。我们表明，WCC 在短暂结合启动子后，可直接响应蓝光调控 fl 的转录。我们提出，fl 在营养菌丝中受到 FLD 的抑制，并且在光照暴露和 WCC 激活后，抑制作用被解除。光照暴露后，fl mRNA 在营养菌丝中的增加，以及调节 FL 蛋白的相应增加，应该会促进分生孢子形成途径的激活。fl 的光激活为粗糙脉孢菌中蓝光照诱导分生孢子形成提供了一个简单的机制，该机制可能在其他真菌中也起作用。
