Fig. 4: Two-photon in vivo imaging of blood vessel-guided migration and blood vessel-independent migration.

a Schematic illustration of two-photon imaging of living embryos we performed. We introduced the rDIO system into Flt1-DsRed mice at E15 and performed imaging 2 days later. (b–e) Reconstructed two-photon images. The range of Z axis to reconstruct the image is shown on the left (blue region, the scale of depth from the brain surface is shown on the right side of the box). The time stamps are shown in h:mm format. (b, c) Two examples of in vivo imaging showing blood vessel-guided migration of GFP-positive cells (arrows). The upper and lower panels represent xy and xz planes of the same 3D space, respectively. The movie versions of b, c are provided as Supplementary Movie 8 and 9, respectively. (d, e) Two examples of in vivo imaging showing blood vessel independent migration of GFP-positive cells (arrows). The merged images of GFP and DsRed, as well as DsRed single channel, are shown in the upper and lower panels, respectively. The broken lines in the lower panels represent the outlines of GFP-positive cells. The movie versions of d, e are provided as Supplementary Movie 11 and 12, respectively. Scale bars, 20 µm.