Pax6 is expressed in BLBP clustered cells. A, Pax6 expression matched the location of clusters of BLBP⁺ cells. B, The combination of patch recording with biocytin staining (1) and immunocytochemistry for Pax6 (2) shows that clustered precursors expressed the transcription factor Pax6 (3). The inset in B1 is a stack of sections showing the whole cluster of dye-coupled cells. The main images are confocal optical sections. C, BLBP (1) and Pax6 (2) expression in the CG. The merged images show that most BLBP⁺ cells coexpressed Pax6 (3). Scale bars: A, 30 μm; B, C, 20 μm.