Figure 8

In the absence of Laminin, FBMNs fail to speed up and do not reorient centrosomes. (A, B) Maximum intensity projections from timelapse recordings started at 24 hpf of wild-type (A) and lamininα1-/- (B) tg(isl1:GFP) (green) embryos stained with BODIPY TR methyl ester dye (red) reveal that FBMNs migrate ventrally down to the ventral limit of the hindbrain (dotted line) in both the presence and absence of Laminin (compare blue outlined FBMNs), they do not speed up in the absence of Laminin (compare magenta outlined FBMNs) and some even mismigrate anteriorly (white outlined FBMN). (C) lamininα1-/-; tg(isl1:GFP) embryos stained for γ-tubulin show centrosomes pointing medially in FBMNs both inside the hindbrain (white arrow) and outside the hindbrain (blue arrows). The upper panel is an XY section while lower panel is a reconstructed YZ section at the level of the FBMN indicated by the blue arrow in the upper panel with the hindbrain outlined (dotted line) to show that the indicated FBMN is outside the hindbrain. (D) Quantification of centrosome positioning in lamininα1-/- embryos shows that centrosomes fail to reorient in the absence of Laminin (compare to Figure 2D). HB, hindbrain.