VE-1 regulation of MAPK signaling controls sexual development in .

UNLABELLED

Sexual reproduction in fungi allows genetic recombination and increases genetic diversity, allowing adaptation and survival. The velvet complex is a fungal-specific protein assembly that regulates development, pathogenesis, and secondary metabolism in response to environmental cues, such as light. In , this complex comprises VE-1, VE-2, and LAE-1. Deletion of or , but not , leads to increased conidiation (asexual spore formation) and reduced sexual development. Mutants lacking and/or are female sterile and male fertile, indicating that a VE-1/VE-2 complex regulates the development of female structures. During sexual development, we observed differential regulation of 2,117 genes in dark and 4,364 genes in light between the wild type and the ∆ strain. The pheromone response and cell wall integrity pathways were downregulated in the ∆ mutant, especially in light. Additionally, we found reduced levels of both total and phosphorylated MAK-1 and MAK-2 kinases. experiments demonstrated the binding of VE-1 and VE-2 to the promoters of and , suggesting a direct regulatory role of VE-1/VE-2 in the transcriptional control of MAPK genes to regulate sexual development. Deletion of the photosensor gene prevented the light-dependent inhibition of sexual development in the ∆ mutant by increasing transcription of the pheromone response and cell wall integrity pathway genes to the levels in the dark. Our results support the proposal that the regulation of the MAP kinase pathways by the VE-1/VE-2 complex is a key element in transcriptional regulation that occurs during sexual development.

IMPORTANCE

Sexual reproduction generates new gene combinations and novel phenotypic traits and facilitates evolution. Induction of sexual development in fungi is often regulated by environmental conditions, such as the presence of light and nutrients. The velvet protein complex coordinates internal cues and environmental signals to regulate development. We have found that VE-1, a component of the velvet complex, regulates transcription during sexual development in the fungus . VE-1 regulates the transcription of many genes, including those involved in mitogen-activated protein kinase (MAPK) signaling pathways that are essential in the regulation of sexual development, and regulates the activity of the MAPK pathway. Our findings provide valuable insights into how fungi respond to environmental signals and integrate them into their reproductive processes.