Figure 1. Immunohistochemical Localization of Sam68 in Embryonic Mice.

(A) Embryonic mice were removed from pregnant dams at E14.5 and E16.5, fixed in 4% paraformaldehyde, and embedded in paraffin. The entire embryo was immunostained with the AD1 anti-Sam68 antibody and counterstained with methyl green, and the image was captured at ×1.2 magnification.

(B) Embryonic soft tissues from the brain, heart and gut were stained with hematoxylin (left) and immunostained with anti-Sam68 antibody (right), and images were captured at ×20 magnification.

(C) Intense anti-Sam68 immunoreactivity was seen in chondrocytes in the nasal septum (panels A–D), in developing vertebra (panels E–H), and in the femoral epiphysis (panels I–K), as well as in diaphyseal osteoblasts (panel L). Adjacent sections were stained with hematoxylin and eosin (panels A, E, and I) or with antibody preadsorbed with the immunizing peptide (panels B, F, and J). Sam68 was localized primarily in the nucleus of cells in a variety of tissues but was also found occasionally in the cytoplasm. Magnification at source ×20, except for panels D, H, and L, which were ×40. Staining patterns are representative of three to five embryos.