Figure 6

Figure 6

Spatial and temporal normal stress variations within the zebrafish neural rod during development. (a) Left panel: Confocal section of a PLL-Cy3 PAAm bead (white box) within the neural rod embedded between cells of the otic placode (oc) at the 10-somite stage (14 hpf) and the 12-somite stage (15 hpf). Right panel: 3D representation of the normal stress distribution for the entire imaging period at 14 hpf and 15 hpf, respectively. Sampling interval: 2 min at 14 hpf, 5 min at 15 hpf. (b) Left panel: Confocal section of a PLL-Cy3 PAAm bead (white box) embedded (in the same embryo as shown in panel a) close to the midline (ml) of the neural rod (nr) at the 10-somite stage and the 12-somite stage. Right panel: 3D representation of the normal stress distribution over the entire imaging period at 14 hpf and 15 hpf, respectively. Sampling interval: 2 min at 14 hpf, 5 min at 15 hpf. Note that positive normal stress values correspond with tensile stresses. (c) Left panel: Confocal section of a PLL-Cy3 PAAm bead (white box) close to the midline (ml) of the neural rod at 14 hpf. Inset: Identical bead after movement towards the basal part of the neural rod at the end of the imaging period at 14.5 hpf. Right panel: 3D representation of the normal stress distribution for the entire imaging period. Sampling interval: 3 min. (d) Left panel: Confocal section of a PLL-Cy3 PAAm bead trapped in the developing midbrain-hindrain (mbh) of the neural rod at 19 hpf. The dashed lines indicate the border of the mbh. Right panel: 3D representation of the normal stress distribution for the entire imaging period. Sampling interval: 2 min. (a–d) Confocal images: anterior (A) and posterior (P) direction is always marked in the image. PLL-Cy3 PAAm bead (magenta label) and cell membranes (GFP labeled; green). Scale bar, 30 µm. Note that in the images to the right amplified values which were normalized by absolute maximum values are depicted (see descriptions in the text).