title: Regulation of conidiation by light in Aspergillus nidulans.
abstract: Light regulates several aspects of the biology of many organisms, including the balance between asexual and sexual development in some fungi. To understand how light regulates fungal development at the molecular level we have used Aspergillus nidulans as a model. We have performed a genome-wide expression analysis that has allowed us to identify >400 genes upregulated and >100 genes downregulated by light in developmentally competent mycelium. Among the upregulated genes were genes required for the regulation of asexual development, one of the major biological responses to light in A. nidulans, which is a pathway controlled by the master regulatory gene brlA. The expression of brlA, like conidiation, is induced by light. A detailed analysis of brlA light regulation revealed increased expression after short exposures with a maximum after 60 min of light followed by photoadaptation with longer light exposures. In addition to brlA, genes flbA-C and fluG are also light regulated, and flbA-C are required for the correct light-dependent regulation of the upstream regulator fluG. We have found that light induction of brlA required the photoreceptor complex composed of a phytochrome FphA, and the white-collar homologs LreA and LreB, and the fluffy genes flbA-C. We propose that the activation of regulatory genes by light is the key event in the activation of asexual development by light in A. nidulans.
authors.affiliation: Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Sevilla, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Ruger-Herreros
authors.forename: Julio
authors.initials: J
authors.lastname: Rodríguez-Romero
authors.forename: Raul
authors.initials: R
authors.lastname: Fernández-Barranco
authors.forename: María
authors.initials: M
authors.lastname: Olmedo
authors.forename: Reinhard
authors.initials: R
authors.lastname: Fischer
authors.forename: Luis M
authors.initials: LM
authors.lastname: Corrochano
authors.forename: David
authors.initials: D
authors.lastname: Canovas
mesh_terms: D001233:Aspergillus nidulans / Q000235:genetics* / Q000528:radiation effects*; D005656:Fungal Proteins / Q000235:genetics; D015966:Gene Expression Regulation, Fungal / Q000528:radiation effects*; D016681:Genome, Fungal / Q000235:genetics; D008027:Light; D020283:Photoreceptors, Microbial / Q000235:genetics; D012100:Reproduction, Asexual / Q000235:genetics / Q000528:radiation effects; D013172:Spores, Fungal / Q000235:genetics / Q000528:radiation effects; D015533:Transcriptional Activation / Q000528:radiation effects
chemical_list: D005656:Fungal Proteins; D020283:Photoreceptors, Microbial