Fig. 8. Cellular localization of HB-EGF (A) and ErbB1 and ErbB4 (B) in hamster preimplantation embryos. Various stages of hamster preimplantation embryos were fixed, permeabilized and incubated with polyclonal HB-EGF, ErbB1 or ErbB4 antibodies. Localization of antigens (red) and nuclei (blue) were visualized using TRITC-conjugated secondary antibodies and Hoechst 33,342, respectively. Indirect immunofluorescence staining of HB-EGF, ErbB1 and ErbB4 was visualized by scanning laser confocal microscopy with 6 µm optical sections. HB-EGF was mainly in the cell cytoplasm of both ICM (inner cell mass) and trophectoderm (Tr) cells of the blastocyst (A). Both ErbB1 and ErbB4 were mainly in the cell surface of two-cell, four-cell and eight-cell embryos (B). At the blastocyst stage ErbB1 was present in the cell surface of Tr cells only. However, ErbB4 was present in both the surface and the cytoplasm of blastocyst Tr cells (B).

Return to article