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Induction of string rescues the neuroblast proliferation defect in trol mutant animals
Author(s) -
Park Youngji,
Ng Cristina,
Datta Sumana
Publication year - 2003
Publication title -
genesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.093
H-Index - 110
eISSN - 1526-968X
pISSN - 1526-954X
DOI - 10.1002/gene.10216
Subject(s) - neuroblast , mutant , biology , microbiology and biotechnology , genetics , neurogenesis , gene
Abstract Summary: 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. genesis 36:187–195, 2003. © 2003 Wiley‐Liss, Inc.