Fig. 3. A fissure was induced to form by the posterior border cells. A group of cells taken from near –1 of a quail donor was inserted into the level –1.5 of a chicken host. This manipulation resulted in the ectopic formation of a fissure with supernumerary somites along it (brackets). Sixteen out of 34 specimens showed distribution of the quail cells confined to the posterior region of the ectopic border (A), whereas 18 embryos had the donor cells spanning the border (B). No embryo was observed where the graft was located only anteriorly to the ectopic fissure. A; A dorsal view under a dissecting microscope. (A',B,C) A horizontal section stained with QCPN antibody to visualize the quail cells (brown, arrowheads). Anterior at top. (C) Control isotopic graft (–1.5 into –1.5).

Return to article