Affiliation:
1. Department of Plant Pathology and Microbiology, Program in Biochemistry and Molecular Biology, University of California, Riverside, California 92521
Abstract
Abstract
Here we characterize the relationship between the PRE-2 pheromone receptor and its ligand, CCG-4, and the general requirements for receptors, pheromones, G proteins, and mating type genes during fusion of opposite mating-type cells and sexual sporulation in the multicellular fungus Neurospora crassa. PRE-2 is highly expressed in mat a cells and is localized in male and female reproductive structures. Δpre-2 mat a females do not respond chemotropically to mat A males (conidia) or form mature fruiting bodies (perithecia) or meiotic progeny (ascospores). Strains with swapped identity due to heterologous expression of pre-2 or ccg-4 behave normally in crosses with opposite mating-type strains. Coexpression of pre-2 and ccg-4 in the mat A background leads to self-attraction and development of barren perithecia without ascospores. Further perithecial development is achieved by inactivation of Sad-1, a gene required for meiotic gene silencing. Findings from studies involving forced heterokaryons of opposite mating-type strains show that presence of one receptor and its compatible pheromone is necessary and sufficient for perithecial development and ascospore production. Taken together, the results demonstrate that although receptors and pheromones control sexual identity, the mating-type genes (mat A and mat a) must be in two different nuclei to allow meiosis and sexual sporulation to occur.
Publisher
Oxford University Press (OUP)
Reference54 articles.
1. Biology and genetics of vegetative incompatibility in fungi;Aanen,2010
2. Gene replacements at the his-3 locus of Neurospora crassa;Aramayo;Fungal Genet. Newsl.,1996
3. Heterologous expression of mating-type genes in filamentous fungi;Arnaise;Proc. Natl. Acad. Sci. USA,1993
4. Light induction of the clock-controlled gene ccg-1 is not transduced through the circadian clock in Neurospora crassa;Arpaia;Mol. Gen. Genet.,1995
5. A walk-through of the yeast mating pheromone response pathway;Bardwell;Peptides,2005