The embryonic Nkx2.1-derived OL lineage is rapidly eliminated
during postnatal life. (a, b) In Nkx2.1-Cre/
Rosa26R-GFP mice GFP+ (green), Sox10+ (red) double-positive OLPs
are already a minority in the P10 cortex (arrows in a), and their
contribution drops to zero by P80. (c, d) At P10 practically all
OLPs in ventral regions such as the septum are derived from
Nkx2.1-expressing (MGE/AEP-derived) precursors (GFP, Sox10
double-positive; yellow nuclei in c) but even here they are
replaced by other populations (GFP-negative) by P80. (e-j) The
proportional contributions of the three different populations of Sox10+ OL
lineage cells are presented as percentage of the total number of Sox10+ cells in
each region (average± standard deviation). OLs/OLPs derived from
Nkx2.1-expressing precursors are largely eliminated between
birth and adulthood from most regions examined. OLs/OLPs generated from cortical
precursors (Emx1-derived) remain within the cortex at all
stages. Gsh2-expressing precursors give rise to OLs/OLPs that
spread throughout the telencephalon. POA, preoptic area; MC, motor cortex; AC,
anterior commissure; LOT, lateral olfactory tract; CC, corpus callosum. Scale
bar: 100 μm.