Figure 4

BLECs depletion decreases peripheral transport of mA?42 to the pronephros. (A) A schematic diagram of zebrafish 3 dpf larvae with dorsal view. Dotted box depicts the loop structure of BLECs in the optic tectum. Blue lines depict the pronephros. (B,C) Confocal fluorescence images of the brain optic tectum region with Tg(prox1a:TagRFP); Tg(fli1a:EGFP) that labels BLECs and brain vasculatures simultaneously. Control morphant (B) and ccbe1 morphant (C) at 3 dpf with BLECs depleted in the brain with intact vasculatures. Scale bar in C = 50 ?m. (D?G) Dorsal view of the larval brains of control (D,E) and ccbe1 morphants (F,G) 4 h after A?42 injection at 3 dpf. Red fluorescence represents A?42-HiLyte Fluor 647. mA?42 is seen in BLECs (arrowheads) in the control morphants (D) but not in the ccbe1 morphants (F). (D?,E?,F?,G?) Confocal images of zebrafish pronephros (dotted lines) after A?42 (the same fish with brain images). The robust pronephric accumulation of A?42 was detectable in mA?42-injected control (D?), but the reduced pronephric delivery of mA?42 was observed in ccbe1 morphants (F?) compared to control. oA?42 injection into both control and ccbe1 morphants show almost no pronephric accumulation of A?42 (E?,G?). Scale bars = 100 ?m. (H) Quantification of A?42 intensity in the pronephros, normalized by the intensity of non-fluorescent background. (I) Quantification of the relative intensity ratio between the pronephros and hindbrain. Statistical significance was determined by ordinary one-way ANOVA with Tukey?s test. HB, hindbrain; MO, morpholino; OT, optic tectum; n, independent biological samples or animals. Numbers within bar bottom graphs represent n. **, p < 0.01; ****, p < 0.0001; ns, not significant.