P0 is constitutively expressed in the rat neural crest and embryonic nerves and is negatively and positively regulated by axons to generate non-myelin-forming and myelin-forming Schwann cells, respectively.
Mol Cell Neurosci
; 8(5): 336-50, 1997.
Article
de En
| MEDLINE
| ID: mdl-9073396
ABSTRACT
We show that in the rat, the major gene of PNS myelin, P0, is expressed long before myelination in the neural crest, Schwann cell precursors, and embryonic Schwann cells irrespective of whether they will myelinate or not. This myelin-independent P0 expression is constitutive and likely to serve as a specific marker for the Schwann cell lineage. The much higher P0 expression accompanying myelination is therefore not new gene expression but strong up-regulation of preexisting basal levels. We provide new evidence that the up-regulation to myelination-related levels depends on positive extrinsic signals and therefore does not represent a constitutive phenotype. P0 mRNA is not detectable in mature non-myelin-forming Schwann cells of the sympathetic trunk, but is detectable after transection, indicating that there is a P0-inhibitory signal associated with mature unmyelinated axons. Thus, the regulation of the P0 gene is complex, encompassing extrinsically signaled amplification superimposed on a highly lineage-specific and constitutive basal expression.
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Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Cellules de Schwann
/
Axones
/
Protéine P0 de la myéline
/
Embryon de mammifère
/
Gaine de myéline
/
Système nerveux
/
Crête neurale
Limites:
Animals
Langue:
En
Journal:
Mol Cell Neurosci
Sujet du journal:
BIOLOGIA MOLECULAR
/
NEUROLOGIA
Année:
1997
Type de document:
Article
Pays d'affiliation:
Royaume-Uni