Fig. 5. Upregulation of pre-placodal markers in anterior epiblast by grafting to the pre-placodal region. (A) Anterior epiblast was isolated from HH stage 3⁺-4 quail embryos and grafted into chick hosts at 0-4 ss. Grafts were placed either adjacent to the neural plate at the level of the presumptive trigeminal placode, or lateral to the presumptive trigeminal placode. (B) Embryos were examined after 4 or 8 hours with a pan-Distalless antibody (pan-Dll) or an Eya2 probe, together with QCPN antibody to label quail tissue. Grafts adjacent to the neural plate (trigeminal) express both pan-Dll and Eya2 after 8 hours. Grafts lateral to the neural plate do not express either marker after 4 or 8 hours.