Bioinformatic identification of Ustilago maydis meiosis genes

Investigating Host Induced Meiosis in a Fungal Plant Pathogen

“…An overview of how meiosis proceeds in U. maydis was presented by Donaldson and Saville (2008). Since the early stages of meiosis occur in planta and meiosis is temporally linked to the formation of thick walled dormant teliospores, direct microscopic observation of meiotic events has not been possible.…”

“…Bioinformatic comparisons have determined that U. maydis does not possess an ortholog to Ime1, the master regulator of meiosis in S. cerevisiae (Donaldson & Saville, 2008). However, an ortholog to Ste11, the key transcription factor in S. pombe, is present in U. maydis.…”

“…Zahiri et al (2005) proposed that the dormant teliospore is in a premeiotic state and that it begins meiosis immediately upon induction of germination. However, Donaldson and Saville (2008) proposed that DNA replication occurred before karyogamy, while the cell is still in planta. This means that the initial steps of meiosis up to prophase I would occur before the teliospore enters dormancy, with the cell arresting at the pachytene checkpoint (Donaldson & Saville, 2008).…”

“…However, Donaldson and Saville (2008) proposed that DNA replication occurred before karyogamy, while the cell is still in planta. This means that the initial steps of meiosis up to prophase I would occur before the teliospore enters dormancy, with the cell arresting at the pachytene checkpoint (Donaldson & Saville, 2008). This would be consistent with the observation that as the basidium forms, the cell is already in late prophase I, clearing the pachytene checkpoint and beginning meiotic divisions only a short time after induction of germination, and before any new protein synthesis has been detected in the teliospore (Donaldson & Saville, 2008).…”

“…An annotated version of the genome sequence of U. maydis was released in 2007 (Kämper et al, 2006) and the annotation continues to be improved (e.g. Donaldson & Saville, 2008;Doyle et al, 2011;Ho et al, 2007;Kronstad, 2008;Morrison et al, in preparation). This allows molecular manipulation of U. maydis outside the host, followed by molecular analysis in the host.…”