Fig. 9.

Control cases Q320 (a–i) and Q278 (j–r), sacrificed at HH37 and HH38, respectively, processed for Tbr1 ISH and QCPN IMR, and sectioned in a standard horizontal plane. a Drawing of the Q320 graft extent relative to the prosencephalic fate map, inciding on prospective habenula, thalamus and a small part of non-eminential prethalamus. b Schema of the Q320 chimeric brain, illustrating the plane of the sections shown in (c–i). c–i Dorso-ventral section series across the eminential region and some targets of eminential migrations of Q320, showing lack of QCPN-labeled cells. j Drawing of the Q278 graft extent relative to the prosencephalic fate map, inciding on prospective habenula and thalamus. k Schema of the Q320 chimeric brain, illustrating the plane of the sections shown in (l–r). l–r Dorso-ventral section series across the eminential region and some targets of eminential migrations of Q278, showing lack of QCPN-labeled cells. Blue arrowheads indicate the ventricular borders of the graft. Scale bars in a, 250 μm, b, 5 mm, c-i, and l-r 150 μm