Serglycin proteoglycan synthesis in the murine uterine decidua and early embryo

This study has explored the localization and synthesis of the serglycin pro teoglycan in the murine embryo and uterine decidua during midgestation. Emb ryos in deciduae were subjected to in situ hybridization with cRNA probes a nd to immunohistochemical detection with a specific antibody against murine serglycin. Adherent decidual cell cultures were prepared from freshly isol ated deciduae. Proteoglycan biosynthesis was investigated by labeling intac t deciduae and decidual cultures with S-35-sulfate. Serglycin mRNA was dete cted by in situ hybridization throughout the mesometrial portion and at the periphery of the antimesometrial portion of the decidua at Embryonic Day ( E) 8.5, and in the parietal endoderm surrounding the embryo. Serglycin mRNA was detected in fetal liver at E11.5-E14.5. Serglycin was detected by immu nohistochemistry in decidua and parietal endoderm at E8.5 and in liver at E 13.5. Most of the proteoglycans synthesized by cultured intact deciduae (78 %) and adherent decidual cultures (91%) were secreted into the medium. Serg lycin proteoglycan may play an important role in uterine decidual function during early postimplantation development.