Fig. 3. Effect of Xt^J mutation on tangential cell migration. (A,B) The E10.5 Xt^J/Xt^J telencephalon strip labeled with rhodamine (asterisk) and cultured for 2 days. The boundary between the neocortex and the GE is visualized with anti-reticulon 1 antibody (green in A). Rhodamine-labeled cells create an ectopic cluster (arrowhead) in the neocortex instead of migrating towards the presumptive LOT area. (C) Co-culture in which the dorsal neocortex from a green mouse is combined with the ventral neocortex in the Xt^J/Xt^J strip. GFP-expressing cells migrate into the ventral neocortex of the Xt^J/Xt^J mouse. (D) Co-culture in which the dorsal cortex from an Xt^J/Xt^J green mouse is combined with the ventral neocortex in the wild-type strip. Xt^J/Xt^J cells barely migrate into the wild-type ventral neocortex. Arrows indicate the ventral direction of the explants. The white broken lines outline the explants, and green broken lines show the borderlines between explants. Scale bars: 500 µm.