Fig. 5. The level of ß-catenin in 2-cell stage embryos is controlled by the same mechanism as in somatic cells. (A) Involvement of the proteasome. The presence (+) or absence (–) of maternal E-cadherin (E-cadherin^mat) in the embryos analyzed is indicated, as is the presence (+) or absence (–) of the proteasome inhibitor MG132 (5 µM). The monoclonal ß-catenin antibody (ß-catenin Ab) was used for staining (+), except where it was omitted (–) to determine background levels of staining. Secondary antibody was used in every staining. Scale bar: 10 µm. (B) Transcripts for proteins interacting with ß-catenin in the cytoplasm or nucleus are present in oocytes and early embryos. Names of the transcripts are indicated to the left of the figure.