QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online 5 January 2006
doi: 10.1242/dev.02229

This Article Figures Only Full Text Full Text (PDF) All Versions of this Article: dev.02229v1 133/3/429    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Mettler, U. Articles by Urban, J. Search for Related Content PubMed PubMed Citation Articles by Mettler, U. Articles by Urban, J. Social Bookmarking                         What's this?

Timing of identity: spatiotemporal regulation of hunchback in neuroblast lineages of Drosophila by Seven-up and Prospero

Institut für Genetik, Universität Mainz, 55099 Mainz, Saarstraße 21, Germany.

^* Author for correspondence (e-mail: jurban{at}uni-mainz.de)

Accepted 29 November 2005

Neural stem cells often generate different cell types in a fixed birth order as a result of temporal specification of the progenitors. In Drosophila, the first temporal identity of most neural stem cells (neuroblasts) in the embryonic ventral nerve cord is specified by the transient expression of the transcription factor Hunchback. When reaching the next temporal identity, this expression is switched off in the neuroblasts by seven up (svp) in a mitosis-dependent manner, but is maintained in their progeny (ganglion mother cells). We show that svp mRNA is already expressed in the neuroblasts before this division. After mitosis, Svp protein accumulates in both cells, but the downregulation of hunchback (hb) occurs only in the neuroblast. In the ganglion mother cell, svp is repressed by Prospero, a transcription factor asymmetrically localised to this cell during mitosis. Thus, the differential regulation of hb between the neuroblasts and the ganglion mother cells is achieved by a mechanism that integrates information created by the asymmetric distribution of a cell-fate determinant upon mitosis (Prospero) and a transcriptional repressor present in both cells (Seven-up). Strikingly, although the complete downregulation of hb is mitosis dependent, the lineage-specific timing of svp upregulation is not.

Key words: Drosophila, Temporal specification, Neuroblast, Seven-up, Prospero, Hunchback

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				T. Tsuji, E. Hasegawa, and T. Isshiki Neuroblast entry into quiescence is regulated intrinsically by the combined action of spatial Hox proteins and temporal identity factors Development, December 1, 2008; 135(23): 3859 - 3869. [Abstract] [Full Text] [PDF]

				J. Jacob, C. Maurange, and A. P. Gould Temporal control of neuronal diversity: common regulatory principles in insects and vertebrates? Development, November 1, 2008; 135(21): 3481 - 3489. [Abstract] [Full Text] [PDF]

				K. D. Tran and C. Q. Doe Pdm and Castor close successive temporal identity windows in the NB3-1 lineage Development, November 1, 2008; 135(21): 3491 - 3499. [Abstract] [Full Text] [PDF]

				T. Hayashi, C. Xu, and R. W. Carthew Cell-type-specific transcription of prospero is controlled by combinatorial signaling in the Drosophila eye Development, August 15, 2008; 135(16): 2787 - 2796. [Abstract] [Full Text] [PDF]

				B. Egger, J. M Chell, and A. H Brand Insights into neural stem cell biology from flies Phil Trans R Soc B, January 12, 2008; 363(1489): 39 - 56. [Abstract] [Full Text] [PDF]