C. albicans white-opaque transcription factor binding recorded in the mammalian gut

Candida albicans is a central fungal component of the human gut microbiota and an opportunistic pathogen. Two C. albicans transcription factors, Wor1 and Efg1, control its ability to colonize the mammalian gut. They are also master regulators of an epigenetic switch required for mating. The mammalian gastrointestinal tract is a complex environment difficult to model in vitro. In C. albicans, it is known that environmental signals can dictate the binding targets of these transcription factors. To study the regulation of transcription factors of C. albicans in the GI tract, a Calling card-seq approach was adopted. This technique allowed us to directly record transcription factor binding that occurred in the mammalian gut. Overall design: C. albicans strains were constructed by tagging transcription factors Efg1, Wor1 and Czf1 with PiggyBac transposase at native loci. These strains were then grown under the conditions described. Transcription factor binding was mapped to the genome using the position of the PiggyBac transposon, which should be reintegrated at sites where the transcription factor-piggyBac transposase fusion protein binds to the genome.