PT - JOURNAL ARTICLE AU - Fruttiger, M. AU - Karlsson, L. AU - Hall, A.C. AU - Abramsson, A. AU - Calver, A.R. AU - Bostrom, H. AU - Willetts, K. AU - Bertold, C.H. AU - Heath, J.K. AU - Betsholtz, C. AU - Richardson, W.D. TI - Defective oligodendrocyte development and severe hypomyelination in PDGF-A knockout mice DP - 1999 Feb 01 TA - Development PG - 457--467 VI - 126 IP - 3 4099 - http://dev.biologists.org/content/126/3/457.short 4100 - http://dev.biologists.org/content/126/3/457.full SO - Development1999 Feb 01; 126 AB - There is a class of oligodendrocyte progenitors, called O-2A progenitors, that is characterized by expression of platelet-derived growth factor α-receptors (PDGFR(α)). It is not known whether all oligodendrocytes are derived from these PDGFRalpha-progenitors or whether a subset(s) of oligodendrocytes develops from a different, PDGFR alpha-negative lineage(s). We investigated the relationship between PDGF and oligodendrogenesis by examining mice that lack either PDGF-A or PDGF-B. PDGF-A null mice had many fewer PDGFR alpha-progenitors than either wild-type or PDGF-B null mice, demonstrating that proliferation of these cells relies heavily (though not exclusively) on PDGF-AA homodimers. PDGF-A-deficient mice also had reduced numbers of oligodendrocytes and a dysmyelinating phenotype (tremor). Not all parts of the central nervous system (CNS) were equally affected in the knockout. For example, there were profound reductions in the numbers of PDGFR alpha-progenitors and oligodendrocytes in the spinal cord and cerebellum, but less severe reductions of both cell types in the medulla. This correlation suggests a close link between PDGFRalpha-progenitors and oligodendrogenesis in most or all parts of the CNS. We also provide evidence that myelin proteolipid protein (PLP/DM-20)-positive cells in the late embryonic brainstem are non-dividing cells, presumably immature oligodendrocytes, and not proliferating precursors.