Migration and differentiation of Nkx-2.2+ oligodendrocyte progenitors in embryonic chicken retina

During early neural development, the Nkx-2.2 homeobox gene is initially ind uced in the ventral ventricular zone of the central nervous system (CNS). A t later stages, Nku-2.2+ cells migrate away into the surrounding regions an d co-express several oligodendrocyte marker genes. Here we report that Nkx- 2.2+ cells also migrate into the avian retina from the optic nerve. These N kx-2.2+ cells are specifically labeled by the early oligodendrocyte markers PDGFR alpha, O4 and GalC, but not the microglial marker QH1 or neuron-spec ific marker MAP-2. These observations provide further evidence that Nkx-2.2 is selectively expressed in migratory oligodendrocyte progenitor cells and that retina oligodendrocytes originate from the ventral diencephalon. (C) 2001 Elsevier Science B.V. All rights reserved.