Dissection of extraembryonic vessels. (A) E11.5 wild-type embryo, showing position of VV and UC. (B) Dissection of UC. Separation of artery and vein is shown. (C) Dissection of VV. YS and midgut loop were removed. White dotted lines indicate points of dissection to isolate vessels. Original magnification ×8 (A), ×40 (B), and ×32 (C). CD, chorion disk; D, distal; Em, embryo proper; FL, fetal liver; P, proximal; PL, placenta.