Fig. 1

The zebrafish glut1b promoter drives expression in brain endothelial cells. Confocal microscopy of a live glut1b:mCherry; fli1a:EGFP double transgenic larva at 6 dpf. (A-C) mCherry is spatially restricted to the brain vasculature (B) and overlays with endothelial GFP expression from fli1a:EGFP (A, C). Shown here is a dorsal view of the brain vasculature (anterior, left). (D-F) mCherry is not expressed in peripheral endothelial cells. Shown here is the larval trunk (dorsal view) with partial inclusion of the mCherry-expressing hindbrain vasculature (anterior, left). (G-N) mCherry is not expressed in the vasculature of circumventricular organs. (G-J) glut1b:mCherry was crossed to cp:EGFP, an enhancer-trap line that expresses GFP in the myelencephalic (white arrow in G) and diencephalic (white arrowhead in G) choroid plexus. The choroid plexus regions are outlined (white dash) in (H). For G-J, albumin Alexa Fluor 647 (pseudo-colored in blue) was injected as a tracer to visualize blood vessels. Confocal images were captured in the plane of GFP expression. Note the lack of colocalization between mCherry (BBB vessels) and blue (all blood vessels) in the choroid plexus. Scale bar in A is 50 µm for all images.