Fig. 8. Distribution of lot cells and projection of olfactory bulb axons in wild-type and netrin 1 or Dcc mutant embryos. Lateral views of hemispheres in wild-type (A-C) and netrin 1 or Dcc mutant embryos (D-F). (A,D) The initial phase of ventral tangential migration of lot cells (magenta) to the dorsal part of the LOT area by E12.5 is indistinguishable among all of the genotypes. (B) At E13.0, netrin 1 expression begins on the rostral surface of the olfactory tubercle in the wild-type telencephalon (blue shaded area), which presumably attracts lot cells further ventrally. (E) In the mutant telencephalon, without netrin 1-Dcc signal, lot cells remain absent from the ventral part of the LOT area. (C,F) From E13.5 onwards, olfactory bulb axons (green) project from the olfactory bulb, following the array of lot cells. In the mutant telencephalon, the ventral pathway of olfactory bulb axons, which is destined to project through the lot cell-vacant area, shows obvious projection errors.