FIG. 7.

Expression of IMP-1, IMP-2, and IMP-3 in mouse and human embryos. (A) Expression of mouse equivalents of IMP-1, IMP-2, and IMP-3 mRNAs was examined by Northern analysis of total RNA from different embryonic (8.5 to 17.5) and postnatal (100) days as indicated. The amount of RNA in each lane is normalized to rRNA content. (B) Western analysis of IMP-1 in mouse embryos at E12.5, E14.5, and E17.5. The amounts of loaded protein in the three lanes are identical, and lane C contains a positive control sample. (C) Immunohistochemical staining of IMP-1 in mouse and human embryos. (a and b) Localization of IMP-1 in mouse epidermis at E12.5. (a) Staining is visible in the basal layer of the developing epidermis at the basal plasma cell membrane, as indicated by the arrow in panel b. (c) Parallel section where the antiserum was preadsorbed with the peptide used for immunization. (d) Localization of IMP-1 in developing mouse muscle at E15.5. (e) Localization of IMP-1 in fetal human skeletal muscle cells (38 weeks). The submembranous staining is indicated by an arrow. (f) Staining of human term placenta shows the expression of IMP-1 in the trophoblast cells. Scale bars, 11 (a), 7 (b), 11 (c), 20 (d), 11 (e), and 11 (f) μm.