Immunocytological studies of L-MAG expression regulation during myelination of embryonic brain cell cocultures.
The myelin-associated glycoprotein (MAG) possesses two isoforms, known as S-MAG and L-MAG. We followed the expression and localization of L-MAG in comparison to myelin basic protein (MBP) during myelination in dissociated embryonic rat brain cell cocultures. Using immunofluorescence microscopy, we observed L-MAG and MBP in oligodendrocyte (OL) cell bodies and processes before and at the onset of myelination. At advanced stages of myelination, L-MAG immunostaining decreased, and subsequently disappeared from OL soma and myelinated internodes, whereas MBP immunoreactivity decreased only in the OL soma. These results are consistent with biochemical studies and provide the first clear demonstration of a transient expression of L-MAG during the early stages of myelination in vitro, providing further evidence that L-MAG plays a role during this period.
Keita
Mahamane
M
Laboratoire de Neurologie CHRU Dupuytren, Limoges, France.
Magy
Laurent
L
Heape
Anthony
A
Richard
Laurence
L
Piaser
Martine
M
Vallat
Jean-Michel
JM
D000818:Animals; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000196:embryology* / Q000378:metabolism* / Q000648:ultrastructure; D018920:Coculture Techniques; D005455:Fluorescent Antibody Technique; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D004676:Myelin Basic Protein / Q000096:biosynthesis; D009186:Myelin Sheath / Q000502:physiology* / Q000648:ultrastructure; D018992:Myelin-Associated Glycoprotein / Q000096:biosynthesis*; D009413:Nerve Fibers, Myelinated / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar
D004676:Myelin Basic Protein; D018992:Myelin-Associated Glycoprotein