The Role of Transcription Factor, Ofi1 in the Regulation of White-Opaque Switching and Filamentation in Candida Albicans

Candida albicans is a fungal pathogen that can cause infections in people are immunocompromised. It can adapt to the host organism through different cellular shape transitions, such as filamentatous growth which plays a critical role in the fungus's virulence and white to opaque switching which play a role in mating. C. albicans is diploid and typically heterozygous at the central regulator locus, MTL, controlling mating type. In addition to homozygosity of MTL genotypes, white-opaque switching is necessary for mating. White and opaque cells are morphologically and genetically distinct, and the difference in gene expression is responsible for the change in their appearance. The adaptation of C. albicans to host niches relies on transcriptional regulatory programs that can be controlled by complex networks of transcription factors. These factors can influence the cell's phenotypic and stability by acting through DNA binding sites or through interlocking feedback loops. Zinc finger cluster transcription factors are a well-known fungal transcription factor family. A novel transcriptional regulator, Ofi1, has been identified as a candidate regulator for both white-opaque switching and filamentation in C. albicans. In white-opaque switching it appears to act downstream of the master regulator Wor1. A comparison of the ofi1Δ/ofi1Δ strain, the Ofi1 activated strain and the wild type strain under different carbon sources and temperatures were assessed. Activation leads to an increase in both processes, while deletion reduces the frequency of white-opaque switching. The aim of the project is to investigate the role of Ofi1 in the transcriptional programs involved in these processes.