title: Developmental transition by spinal cord plasma membranes of embryonic chick from permissive to restrictive substrates for the morphological differentiation of neuroblastoma x glioma hybrid NG108-15 cell.
abstract: Recent studies of spinal cord development and plasticity, in chick, have demonstrated a loss of regenerative ability correlating to embryonic day (E) 13 of the 21-day developmental period. Here we describe membrane fractions from embryonic chick spinal cords as permissive or restrictive substrates for the neuron-like differentiation of neuroblastoma x glioma hybrid NG108-15 cells, in vitro. Plasma membranes were purified from the thoracic spinal cord of embryos at a series of developmental stages (E10-E18). Micro-well plates were coated with the fractions and NG108-15 cells cultured thereon. Cells adhered to the E10-coated wells and began to differentiate after 2 h, becoming highly differentiated, with neurites 2-3 times longer than the diameter of the cell body after 24 h in in culture. In contrast, cells cultured in E18-coated wells remained as clusters of undifferentiated cells of rounded morphology, even after 48 h in culture. As well, the permissive and restrictive plasma membranes were assessed semiquantitatively as the number of adhering cells after 20 h of culture. Adhesion of cells to the substrate decreased as the embryonic age of the plasma membrane substrate increased. Examination of the plasma membrane fractions, using SDS-PAGE, revealed several proteins in the 40-60 kDa range that varied substantially between E12, E14 and E18. Results of this study provide in vitro confirmation of previous in vivo findings; namely, that early embryonic spinal cord is initially permissive for neuritic outgrowth becoming restrictive around E13.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Zoology, University of British Columbia, Vancouver, Canada.
authors.forename: D W
authors.initials: DW
authors.lastname: Ethell
authors.forename: J D
authors.initials: JD
authors.lastname: Steeves
authors.forename: L M
authors.initials: LM
authors.lastname: Jordan
authors.forename: K W
authors.initials: KW
authors.lastname: Cheng
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002458:Cell Fractionation; D002462:Cell Membrane / Q000502:physiology* / Q000648:ultrastructure; D002642:Chick Embryo; D004591:Electrophoresis, Polyacrylamide Gel; D005910:Glioma; D006822:Hybrid Cells / Q000166:cytology; D008565:Membrane Proteins / Q000302:isolation & purification / Q000494:pharmacology; D008970:Molecular Weight; D009419:Nerve Tissue Proteins / Q000302:isolation & purification / Q000494:pharmacology; D016501:Neurites / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D009447:Neuroblastoma; D013116:Spinal Cord / Q000196:embryology*; D014407:Tumor Cells, Cultured
chemical_list: D008565:Membrane Proteins; D009419:Nerve Tissue Proteins