| The Drosophila Myb protein, DMyb, is a transcription factor important for cell proliferation and development. Using immunofluorescence, a comprehensive analysis of the localization and degradation of the DMyb protein revealed that DMyb is present in nuclei during S-phase of all mitotically active tissues throughout embryogenesis and larval development. We also observed the degradation of the DMyb protein during mitosis. We conclude that cell-cycle specific degradation of DMyb is likely to be utilized as a key regulatory mechanism of the protein.;Using similar techniques we determined that DMyb is required for proper mitosis and nuclear migration in the precellular embryo. Using partial loss of function mutations we discovered an essential role for Dm myb in controlling viability as well as regulating cell cycle progression and maintaining genomic stability. We have determined that loss of Dm myb function results in an array of mitotic defects in early embryos, including disturbance of the timing and coordination of the nuclear cycles, abnormal mitotic figures, defects in spindle formation, and centrosome number.;RNA expression profiling was used to determine the maternal transcriptional targets of DMyb. We found that a small number of genes are regulated by DMyb during oogenesis. One target Glutamine Synthetase I ( GsI) causes similar mitotic defects to Dm myb when mutated. We also discovered a physiological interaction between DMyb and GsI. |
