Global Gene Expression of Post-Senescent Telomerase-Negative ter1 Δ Strain of Ustilago maydis .

We analyzed the global expression patterns of telomerase-negative mutants from haploid cells of Ustilago maydis to identify the gene network required for cell survival in the absence of telomerase. Mutations in either of the telomerase core subunits ( trt1 and ter1 ) of the dimorphic fungus U. maydis cause deficiencies in teliospore formation. We report the global transcriptome analysis of two ter1 Δ survivor strains of U. maydis , revealing the deregulation of telomerase-deleted responses (TDR) genes, such as DNA-damage response, stress response, cell cycle, subtelomeric, and proximal telomere genes. Other differentially expressed genes (DEGs) found in the ter1 Δ survivor strains were related to pathogenic lifestyle factors, plant-pathogen crosstalk, iron uptake, meiosis, and melanin synthesis. The two ter1 Δ survivors were phenotypically comparable, yet DEGs were identified when comparing these strains. Our findings suggest that teliospore formation in U. maydis is controlled by key pathogenic lifestyle and meiosis genes.