Misexpression of basic helix-loop-helix genes in the murine cerebral cortex affects cell fate choices and neuronal survival

To investigate the role(s) of basic helix-loop-helix genes (bHLH) genes in the developing murine cerebral cortex, Mash1, Math2, Math3, Neurogenin1 (Ng n1), Ngn2, NeuroD, NeuroD2 and Id1 were transduced in vivo into the embryon ic and postnatal cerebral cortex using retrovirus vectors. The morphology a nd location of infected cells were analyzed at postnatal stages. The data i ndicate that a subset of bHLH genes are capable of regulating the choice of neuronal versus glial fate and that, when misexpressed, they can be delete rious to the survival of differentiating neurons, but not glia.