SPATIAL REGULATION OF HYPHAL MORPHOGENESIS
Fungal spores germinate to form long, tubular hyphae that are typically composed of multinucleate cells. Amongst the morphogenetic events that contribute to hyphal organization are the establishment and maintenance of cellular polarity, and the formation of cellular compartments via septation. Each of these events involves localized cell wall deposition at a discrete cell surface site. We wish to determine how these sites are specified and used to recruit the morphogenetic machinery.
THE FUNGAL DNA DAMAGE RESPONSE
The DNA damage response is protective mechanism that ensures the maintenance of genome integrity during cellular reproduction. The response encompasses mechanisms that promote the repair and/or tolerance of DNA damage. We have recently uncovered an intimate link between hyphal morphogenesis and the fungal DNA damage response. In particular, we found that activation of the response inhibits septum formation in a checkpoint-dependent manner. We wish to determine how activation of the checkpoint pathway affects the timing of septation.
CHARACTERIZATION OF SEPB
The sepB gene was initially identified by a mutation that blocks septum formation. We subsequently determined that the SEPB protein is required for chromosomal DNA metabolism, and that the septation defect was an indirect effect caused by activation of the DNA damage response. Orthologues of SEPB are found in both animals and plants, and we suspect that they play a conserved role in the maintenance of genome integrity.