AGM immunostaining for mTAB2.

(A) Western blot analysis on mouse fibroblast (NIH-3T3) and myeloid (MPRO) cell lines and human B-lymphoid (ROS17) and T-lymphoid (Jurkat) cell lines shows that the antibody raised against human TAB2 recognizes a single protein band with the expected molecular mass of 77 kDa in both the human and mouse protein lysates. (B) Immunohistochemistry with the anti-TAB2 antibody was performed on 6 to 8 μM transverse cryosections of E12 embryos at the level of the AGM. Expression of mTAB2 was detected in the endothelium of the E11 (not shown) and E12 dorsal aorta and in some cells surrounding the dorsal aorta. Original magnification, × 200. TAB2 staining was visualized with peroxidase substrate DAB chromogen and sections were counterstained with hematoxylin.