e mërkurë, prill 06, 2005

Multipotency factor Id'ed

Neural crest precursor cells appear in vertebrate embryos around mid-gastrulation and are maintained as multipotent cells until neural tube closure, after which they migrate and differentiate into the peripheral nervous system and other tissues. Light and colleagues now report that, in Xenopus, Id3 acts downstream of Myc to prevent neural crest precursor cells prematurely losing their multipotency (see p. 1831). Myc has been previously shown to prevent premature cell fate decisions in neural crest precursor cells. Light et al. show that the morpholino-mediated knockdown of Id3 – Id proteins are negative regulators of bHLH transcription factors – produces embryos in which CNS progenitors replace neural crest. Conversely, forced expression of Id3 maintains neural precursors in an undifferentiated state. Thus, Id3 helps to maintain neural crest stem cells until the appropriate time for them to respond to differentiation signals. Similar strategies may help to maintain other stem cell populations.