Western blotting and Immunohistochemistry of SOLD1. (A) Western blot analysis of recombinant SOLD1 proteins. Purified ovSOLD1 and caSOLD1 (1 ng each) were loaded onto separate lanes. The proteins were separated by SDS--PAGE and specific proteins were detected by western blot analysis using anti-boSOLD1 antibody. (B--G) Protein localization of SOLD1 in ovine placentomes on day 45 of gestation. (B, D and F) The ovSOLD1 protein was detected by immunohistochemistry. A custom-made anti-boSOLD1 antibody was used. (C, E and G) Negative control (NC) using rabbit pre-immune serum instead of the primary antibody. (H--M) Localization of SOLD1 protein in caprine placentomes on day 50 of gestation. (H, J and L) The caSOLD1 protein was detected by immunohistochemistry using a custom-made anti-boSOLD1 antibody. (I, K and M) (NC using rabbit preimmune serum instead of the primary antibody. The key to abbreviations is as in Figure 3. Scale bars = 100 μm (B--E and H--K) and 50 μm (F, G, L and M).