The role of ErbB receptor signaling in cell fate decisions by cortical progenitors: Evidence for a biased, lineage-based responsiveness to different ligands

We recently identified the required collaborative signaling of TGF alpha and collagen type IV to regulate cell fate choice in the cerebral cortex, measured by the expression of the limbic system associated membrane protein (LAMP) by nonlimbic, sensorimotor progenitors. We show that activation of different members of the erbB receptor family can similarly modulate the specification of cortical area fate. The region of the cerebral wall from which progenitor cells arise does not Influence the response to the neuregulin-1 or TGF alpha, but a subpopulation of progenitors is not competent to express LAMP in response to neuregulin-1. The heterogeneity in the responsiveness by progenitors to the two growth factors is reflected in the expression of different repertoires of erbB receptors. Using clonal analysis, we demonstrate that there may be a lineage-dependent mechanism regulating the ability of neuronal progenitors to respond to specific inductive cues that control cell fate.