Proneural bHLH neurogenin 2 differentially regulates Nurrl-induced dopamine neuron differentiation in rat and mouse neural precursor cells in vitro

Roles of Nurrl and neurogenin 2 (Ngn2) have been shown in midbrain dopamine (DA) neuron development. We present here rat and mouse species-dependent differences of Nurrl and Ngn2 actions in DA neuron differentiation. Nurrl exogene expression caused an efficient generation of tyrosine hydroxylase (TH)-positive DA cells from rat neural precursor cells (NPCs). Nurrl-induced TH+ cell yields were low and highly variable depending on the origins of NPCs in mouse cultures. Coexpression of Ngn2 repressed Nurrl-induced generation of TH+ cells in rat cultures. In clear contrast, a robust enhancement in Nurrl-induced DA cell yields was observed in mouse NPCs by Ngn2. These findings imply that DA neurons may develop differently in the midbrains of these two species. (C) 2008 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.