Problem: The goal of this study was to determine if caprine conceptuses express lectin-like receptors for endometrial H-type 1 (HT1) antigen.
Method of study: Conceptus tissues were collected during the apposition, adhesion and attachment phases of placentation and evaluated using immunofluorescence microscopy.
Results: Conceptus staining for the trisaccharide lacto-N-fucopentaose-1 was strong and uniform during apposition of fetal and maternal tissues but changed by day 25 of pregnancy when large aggregates of intense staining were observed. Monoclonal antibodies to galectin-3 did not stain conceptus tissue during the apposition phase but intense punctate staining was observed after day 25. Strong uniform staining for Lewis Y antigen was detected only on day 17 of pregnancy.
Conclusion: Conceptus tissue expresses potential receptors for endometrial HT1 antigen. Carbohydrate–lectin interactions may facilitate attachment of the apical surfaces of uterine epithelial cells and trophectoderm during the early stages of placentation.