Inhibition of goat sperm-zona binding by monoclonal antibodies to a glycoprotein family (ZP4) of porcine zona pellucida

The zona pellucida (ZP) in a majority of species consists of three antigenic families with wide inter species cross reactivity. The glocoproteins of heat solubilized goat zona pellucida (gZP) were isolated into three families by high performance liquid chromatography on a gel filtration column. Their molecular identities were 180, 95 and 75 kDa for gZP1, gZP2 and gZP3 respectively. However under reducing conditions, four zona pellucida fractions of 135, 95, 75 and 42 kDa were observed. The monoclonal antisera Mab-5H4 against porcine ZP4 (a 23 kDa glycoprotein) easily recognized the 180 and 42 kDa gZP fractions. It was also found that the 5H4 antisera strongly inhibited homologous goat sperm-zona binding. Finally, using immunofluorescent staining the goat occytes reacted positively with the 5H4 antisera. The fluorescence was uniform at 1 : 10 antisera dilution but tended to fade at higher dilution’s. Results suggest that the gZP has an antigen epitope correlative to the 5H4 antisera which is involved in sperm-zona interaction and could be a good candidate for the development of a contraceptive vaccine. # 2000 Elsevier Science B.V. All rights reserved.