Figure 4.

Diminished expression of MHC in the skeletal muscle of p21^−/− p57^−m/+ double mutant embryos. Immunofluorescence staining was performed on transverse sections of E18.5 embryos of indicated genotypes with a monoclonal antibody against MHC. MHC expression was visualized with a Texas red-conjugated secondary antibody, and nuclei were stained with DAPI. (A,B) The root of the diaphragm; (C,D) the diaphragm; (E,F) the body wall. Genotypes are indicated above for each column. (in) Intestine; (li) liver.