(A–C) Genetic complementation of oxytocin receptor in the vascular endothelia of oxtlr-deficient embryos. Double transgenic embryos expressing an endothelial Gal4 driver (fli1:Gal4) and a fluorescent reporter protein (UAS:Kaede; green) were injected with transposon-based transgenic vector containing a multicistronic gene expression cassette (UAS:oxtlr-2A-EGFP) allowing simultaneous mosaic coexpression of the oxytocin receptor and EGFP in discrete vascular clones (red). These clones were detected by immunostaining with an anti-EGFP antibody that does not react with the Kaede protein followed by a secondary cy3-conjugated antibody. The asterisk (*) demarcates the location of the neurohypophysis.
(D) Schematic model describing the hypothalamohypophyseal neurovascular connection by local secretion of oxytocin (see text).
CaDI, caudal division of internal carotid; CrDI, cranial division of the internal carotid artery; OA, optic artery; PHS, primary head sinus; PLA, palatocerebral artery.