Figure 5.

(A–AD) Comparisons of in situ hybridization/immunochemical data for three CoP markers at Q26-HH26 in horizontal cryostat sections at four section levels (in each case a single specimen). The markers are identified at the bottom left corner of each panel. Each row of panels [e.g., (A–E)] shows from left to right four section levels (dorsal to ventral sequence) reacted for a particular marker, followed by a pseudocolored image comparing the same marker, but paired with another at the second level studied. The first three rows show different markers in the quail, and the last three rows contain comparable material for the chick, so that panels taken long the vertical columns represent essentially the same section level and are comparable across the species. Insets (A′,F′,K′) show a more dorsal section level, illustrating details of expression of the corresponding marker. Black arrowheads in (N,AC) indicate ventral levels of CoP ventricular zone lacking PAX7 immunoreaction. Asterisks in (D,S) identify Pax6 positive cells in the CoP deep intermediate layer. Numbers between brackets: code of the specimen in our collection. Scale bar in (AC) applies as well to (A–D,F–I,K–N,P–S,U–X,Z–AB). Scale bars = 300 μm.