Lineage, fate, and fate potential of NG2-glia

• NG2 cells represent a progenitor stage within the oligodendrocyte lineage.
• The primary fates of NG2 cells are self-renewal and oligodendrocyte differentiation.
• The NG2 cell fate decision can occur during or shortly after division.
• NG2 cells exhibit lineage plasticity and express some neuronal genes.
• The fate and fate potential of NG2 cells become restricted with age.

NG2 cells represent a fourth major glial cell population in the mammalian central nervous system (CNS). They arise from discrete germinal zones in mid-gestation embryos and expand to occupy the entire CNS parenchyma. Genetic fate mapping studies have shown that oligodendrocytes and a subpopulation of ventral protoplasmic astrocytes arise from NG2 cells. This review describes recent findings on the fate and fate potential of NG2 cells under physiological and pathological conditions. We discuss age-dependent changes in the fate and fate potential of NG2 cells and possible mechanisms that could be involved in restricting their oligodendrocyte differentiation or fate plasticity.This article is part of a Special Issue entitled SI:NG2-glia(Invited only).