Comparative Transcriptomics Highlights New Features of the Iron Starvation Response in the Human Pathogen .

In this work, we used comparative transcriptomics to identify regulatory outliers (ROs) in the human pathogen . ROs are genes that have very different expression patterns compared to their orthologs in other species. From comparative transcriptome analyses of the response of eight yeast species to toxic doses of selenite, a pleiotropic stress inducer, we identified 38 ROs in . Using transcriptome analyses of response to five different stresses, we pointed out five ROs which were more particularly responsive to iron starvation, a process which is very important for virulence. Global chromatin Immunoprecipitation and gene profiling analyses showed that four of these genes are actually new targets of the iron starvation responsive Aft2 transcription factor in . Two of them ( and ) are required for optimal growth in iron limited conditions. In , the orthologs of these two genes are involved in ribosome rescue by the NO GO decay (NGD) pathway. Hence, our results suggest a specific contribution of NGD co-factors to the adaptation to iron starvation.