Fig. 3

Fig. 3. Cxcr4b is the predominant downstream effector of Neurog1 during olfactory cup morphogenesis. (A) cxcr4b whole-mount in situ hybridisation at 12, 15 and 18 hpf in control and neurog1^hi1059 mutant embryos. cxcr4b expression is dramatically reduced or absent in EON progenitors at 12 and 15 hpf in neurog1^hi1059 mutant embryos (white dotted lines) but from 18 hpf the expression of cxcr4b recovers. (B) cxcl12a whole-mount in situ hybridisation at 12, 15 and 18 hpf in control and neurog1^hi1059 mutant embryos, in which cxcl12a expression is not affected. (C) Tracks showing migration of anterior EON of control (black) embryos, neurog1^hi1059 mutant embryos (magenta), neurog1^hi1059 mutant embryos carrying the Tg(-8.4neurog1:cxcr4b) transgene (cyan) and control embryos carrying Tg(-8.4neurog1:cxcr4b) (light blue). Twelve anterior tracks are represented (from four embryos). The origin of the tracks has been arbitrarily set to the intersection of the x/y-axes and the early (coloured) and late (grey) phases of migration have been highlighted. (D) Mean tracks showing migration of anterior EON of the tracks in C. (E) Pairwise PCA scatterplots of morphogenetic parameters extracted from the datasets presented in D. The major difference between control, neurog1^hi1059, and control or neurog1^hi1059 with the rescue transgene (PC1) corresponds to the antero-posterior axis. (F) Clustering analysis of morphogenetic parameters extracted from the datasets presented in D and analysed in E. One cluster, k2, contains virtually exclusively neurog1^hi1059 cells (magenta), whereas cells from control (black), rescue (cyan) and control/rescue (light blue) embryos clustered together in k1, k3 and k4. Scale bars: 100 µm.