Expression of Syk in vascular ECs.

(A) Immunoblot analysis of Syk in vascular ECs. Cell and tissue extracts (10 μg protein) were analyzed by immunoblotting with anti-Syk antibody: wild-type (lane 1) and Syk-deficient mice liver (lane 2), HUVECs (lane 3), BAECs (lane 4), Syk-deficient DT40 chicken B cells (lane 5), wild-type DT40 cells (lane 6), and human Ramos B cells (lane 7). (B) RT-PCR Northern blot analysis of Syk mRNA in Ramos B cell line (lane 1) and HUVECs (lane 2). The positions of Syk and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as control are indicated. (C) Expression of Syk in mouse embryonic ECs. Immunofluorescence microscopy of microvasculature of wild-type and Syk-deficient mice at embryonic day 18.5. ECs were double labeled with anti-Syk antibody and with anti-CD31 antibody as a marker for ECs. Bars = 1.0 μm