Induction of string rescues the neuroblast proliferation defect in trol mutant animals. Academic Article uri icon


  • In trol mutants, neuroblasts fail to exit G1 for S phase. Increasing string expression in trol mutants rescues the number of S phase neuroblasts without an increase in M phase neuroblasts. Decreasing string expression further decreased the number of S phase neuroblasts. Coexpression of cyclin E and string did not produce additional S phase cells. Unlike cyclin E, cdk2, and cdk2AF, elevated expression of neither cyclin A, cyclin D, nor cdk1AF was able to promote S phase progression in arrested neuroblasts, indicating that String-induced activity of a Cyclin A or Cyclin D complex is unlikely to drive trol neuroblasts into S phase. Biochemical analyses revealed a rapid increase of Cyclin E-Cdk2 kinase activity to wild-type levels upon increased string expression. These results suggest that Drosophila Cdc25 may directly or indirectly increase the kinase activity of Cyclin E-Cdk2 complexes in vivo, thus driving arrested neuroblasts into cell division.

published proceedings

  • Genesis

author list (cited authors)

  • Park, Y., Ng, C., & Datta, S

citation count

  • 10

complete list of authors

  • Park, Youngji||Ng, Cristina||Datta, Sumana

publication date

  • August 2003