Gal-1 is expressed throughout the thymus, and ablation of the gal-1 gene did not affect glycosylation of thymocytes or thymic architecture. (A) Immunohistochemistry images of thymus from wild-type (top left) and gal-1^−/− (top right) mice stained with a polyclonal anti–gal-1 antibody and counterstained with hemotoxylin. (B) Control immunohistochemistry images of thymus from wild-type (bottom left) and gal-1^−/− (bottom right) mice stained with rabbit serum and counterstained with hematoxylin. (C,D) Flow cytometric histograms of SNA (C) and PNA (D) staining of wild-type (shaded) and gal-1^−/− (thin line) DP (left), CD4⁺ SP (middle), and CD8⁺ SP (right) thymocyte populations. The numbers represent the mean fluorescent intensity of lectin staining in the wild-type (gray) and gal-1^−/− (black) populations. Note the change in y-axis between histograms. Results represent 2 independent experiments.