LSR expression during embryogenesis. Tissue sections of E11.5 (top), E12.5 (middle), and E13.5 (bottom) mouse embryos were stained with antibodies directed against LSR (red) and CD31 (green). Whole embryos, as well as high-power images of three CNS regions (caudal SC, rostral SC, and forebrain), are shown as well as single-channel images for LSR staining. At E11.5, LSR staining is visualized in CNS blood vessels at the caudal part of the SC only. By E12.5, LSR is expressed throughout the caudal-to-rostral axis of the SC, but not in the forebrain. At E13.5, LSR is expressed in all blood vessels throughout the CNS. Bars: (left) 1.25 mm; (right) 20 µm.