Lack of core 1 O-glycans causes reduced PDPN levels on LECs. (A) Whole mount images of WT or EHC C1galt1^−/− mouse mesentery at E17 with antibodies against Prox-1, Tn, and PDPN. Scale bar, 10 μm. (B) Flow cytometric analyses of cell surface PDPN levels on freshly isolated mesenteric LECs from WT or EHC C1galt1^−/− mice at P1. Dot plots are shown after gating on CD31⁺/Lyve-1⁺ LEC cells. Percentage and mean fluorescence intensity (MFI) (in parenthesis) are indicated for PDPN in each quadrant. (C, left) C1galt1^f/f;tetO-Cre⁺ mice and littermate WT mice were fed a doxycycline diet for 6 weeks, starting at 6-weeks old. Confocal images of ileal cryosections from doxycycline-inducible or littermate control mice with antibodies against PDPN and Lyve-1 are shown. Scale bar, 20 μm. (C, right) Flow cytometric analyses of PDPN on CD31⁺/Lyve-1⁺ isolated mesenteric LECs from doxycycline-inducible or littermate control mice, and (D) CD31⁺/Lyve-1⁺ isolated mesenteric LECs from 12-week-old WT or Clec2^−/− mice. The images and data are representative of at least 3 experiments. E17, embryonic day 17; P1, postnatal day. SSC, side scatter.