seven-up Controls Switching of Transcription Factors that Specify Temporal Identities of Drosophila Neuroblasts

• Published in: Developmental cell Vol. 8; no. 2; pp. 203 - 213
• Main Authors: Kanai, Makoto I., Okabe, Masataka, Hiromi, Yasushi
• Format: Journal Article
• Language: English
• Published: Cambridge, MA Elsevier Inc 01-02-2005; Cell Press
• Subjects: Animals; Animals, Genetically Modified; Biological and medical sciences; Cell Differentiation; Cell differentiation, maturation, development, hematopoiesis; Cell Division; Cell physiology; Central Nervous System - cytology; Central Nervous System - embryology; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Drosophila; Drosophila - cytology; Drosophila - genetics; Drosophila - growth & development; Drosophila - metabolism; Drosophila Proteins - genetics; Drosophila Proteins - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Developmental; Genes, Insect; Kruppel-Like Transcription Factors; Molecular and cellular biology; Multipotent Stem Cells - cytology; Mutation; Neurons - cytology; Receptors, Steroid - genetics; Receptors, Steroid - metabolism; Repressor Proteins - genetics; Repressor Proteins - metabolism; Transcription Factors - genetics; Transcription Factors - metabolism; Regulation(control); Arthropoda; Insecta; Development; Invertebrata; Transcription factor; Neuroblast; Drosophila melanogaster; Diptera; Switching; Drosophilidae
• ISSN: 1534-5807; 1878-1551
• DOI: 10.1016/j.devcel.2004.12.014

Drosophila neuronal stem cell neuroblasts (NB) constantly change character upon division, to produce a different type of progeny at the next division. Transcription factors Hunchback (HB), Krüppel (KR), Pdm (PDM), etc. are expressed sequentially in each NB and act as determinants of birth-order identity. How a NB switches its expression profile from one transcription factor to the next is poorly understood. We show that the HB-to-KR switch is directed by the nuclear receptor Seven-up (SVP). SVP expression is confined to a temporally restricted subsection within the NB’s lineage. Loss of SVP function causes an increase in the number of HB-positive cells within several NB lineages, whereas misexpression of
svp leads to the loss of these early-born neurons. Lineage analysis provides evidence that
svp is required to switch off HB at the proper time. Thus,
svp modifies the self-renewal stem cell program to allow chronological change of cell fates, thereby generating neuronal diversity.