Nanoparticle-mediated SEC deletion. (a) Whole-embryo
and tissue
level views at 48 hpi of the blood vasculature in kdrl:GFP transgenic control embryos, embryos injected with 1 mg/mL clodronic
acid, or embryos injected with liposomes containing 1 mg/mL clodronic
acid (DSPC or DOPC liposomes). Complete deletion of the caudal vein
is observed in embryos injected with DSPC liposomes containing clodronic
acid (brackets and asterisks). (b) Schematic representation of blood
flow in control embryos or embryos injected with DSPC liposomes containing
1 mg/mL clodronic acid. Blue indicates venous or capillary blood vessels,
and red indicates arterial blood vessels. Arrowheads indicate direction
of blood flow (based on observations from Movie S1). The removal of the CV (dashed lines) leads to a rerouting
of blood flow through the DLAV. (c) Quantification of PCV length in
injected embryos. Bar height represents median values, dots represent
individual data points, and brackets indicate significant values (**: p < 0.01, ***: p < 0.001) based on
Kruskal–Wallis and Dunn’s tests with Bonferroni correction
for multiple testing. n = 6 individually injected
embryos per group (in two experiments). (d) Progression of SEC deletion.
Individual frames from Movie S2 at indicated
time points after injection of DSPC liposomes containing 1 mg/mL clodronic
acid, injected into kdrl:GFP transgenic embryos.
SEC fragmentation in this case is observed mostly between 12 hpi and
16 hpi, followed by a gradual loss of fluorescence or removal of cellular
debris. (e) Tissue level view of distribution of DSPC liposomes containing
1 mg/mL clodronic acid at 1 hpi in stab2ibl2 and sibling control embryos. (f) Whole-embryo
and tissue level views at 48 hpi of the blood vasculature in kdrl:GFP transgenic stab2ibl2 and sibling embryos. Embryos were injected with DSPC liposomes
containing 1 mg/mL clodronic acid. Complete deletion of the caudal
vein is observed in sibling control (brackets and asterisks), but
not stab2ibl2 mutant
embryos. (g) Schematic representation of blood flow in sibling control
embryos or stab2ibl2 homozygous
mutants, both injected with DSPC liposomes containing approximately
1 mg/mL clodronic acid. Blue indicates venous or capillary blood vessels,
and red indicates arterial blood vessels. Arrowheads indicate direction
of blood flow (based on observations from Movie S3). The removal of the CV (dashed lines) leads to a rerouting
of blood flow through the DLAV in control embryos but not in stab2ibl2 homozygous mutants.
(h) Quantification of PCV length in injected embryos. Bar height represents
median values, dots represent individual data points, and brackets
indicate significant values (***: p < 0.001) based
on Mann–Whitney test.