20
March 2003
Stem cell fates: Hair trigger
Embryonic epidermis stem cells adopt one of two fates, becoming epidermal cells or hair follicles. In vivo analysis of the signalling pathway involved in epidermal bud formation reveals a delicately balanced system in which the stem cells require simultaneous inputs of stimulatory and inhibitory signals from various neighbouring cell types in order to produce an activated transcription factor that then modifies an adherens junction gene, a gene that codes for the actin filament links between adjacent epithelial cells. The components of this network include the Wnt and noggin signalling pathways, Lef1 transcription complexes and the E-cadherin gene. This work shows how converging signal pathways can provide a remarkable level of control over the fate of various cell lineages. It is easy to imagine how alterations in growth factor signalling in such a complex system might lead to a slight imbalance, resulting in tumour formation.
Links between signal transduction, transcription and
adhesion in epithelial bud development
COLIN JAMORA,
RAMANUJ DASGUPTA, PAWEL KOCIENIEWSKI & ELAINE FUCHS
Nature 422,
317–322 (2003); doi:10.1038/nature01458
| First
Paragraph | Full
Text (HTML / PDF) |
Developmental biology: A hairy situation
YANN BARRANDON
A key step in hair-follicle development
is the rearrangement of epithelial stem cells. It seems that reduced production
of an adhesion protein, through the concerted action of two signalling pathways,
is crucial for this process.
Nature 422, 272–273 (2003);
doi:10.1038/422272a
| Full
Text (HTML / PDF) |
