Parallel gene expression orders during segmentation (top) and neurogenesis (bottom) determine cell fate.

Doe/Elsevier

Click! Even as a snapshot records a moment in time, so too do the progeny of neuronal stem cells record and remember the transcriptional regulatory factors present at the time of their birth. For it is these factors that determine the cells' fate—their temporal identity and spatial destiny.

In the fly, the genes hunchback (hb), pdm1/pdm2 (pdm), and castor (cas) are expressed at different times in the embryonic central nervous system and have been suggested to specify temporal identity of neuroblast daughter cells. Now, Chris Doe and colleagues (University of Oregon, Eugene, OR) propose that sequential expression of these factors defines identity in neuroblast lineages.

Doe and colleagues first add the gene krüppel (Kr) to the proposed temporal cassette, and find that individual...

The Rockefeller University Press
2001
The Rockefeller University Press
2001
You do not currently have access to this content.