Mouse oligospheres: From pre-progenitors to functional oligodendrocytes

To study the biology and repair capacities of mouse oligodendroglial cells, we established cultures of cells purified from neonatal wild-type and 9.6- kb MBP-LacZ transgenic newborn mice cerebral hemispheres as free-floating a ggregates in the continuous presence of neurblastoma conditioned medium (N1 -B104), In vitro analysis indicated that the initial cell preparations were enriched in oligodendrocyte pre-progenitors that expressed PSA-NCAM and GA P-43 but not GD3, O4, NF68 or glial fibrillary acidic protein (GFAP) marker s. These pre-progenitors required increased concentrations of insulin and p rogesterone to allow their survival in vitro. With time in culture, spheres composed of oligodendrocyte pre-progenitors became oligospheres enriched i n oligodendrocyte progenitors expressing GAP-43 and GD3, As well as conserv ing bipotentiality in vitro, these spheres were able to form myelin in vivo after transplantation into the neonatal shiverer mouse brain. Thus, the ol igosphere strategy is a powerful method for generating large populations of mouse oligodendrocyte pre-progenitors and progenitors. The ability to gene rate oligospheres from transgenic mice will be instrumental in the further dissection of the molecular and cellular mechanisms of myelination and remy elination of the central nervous system. J. Neurosci. Res. 58:735-751, 1999 . (C) 1999 Wiley-Liss, Inc.