OOCYTE AND ZYGOTE ZONA-PELLUCIDA PERMEABILITY TO MACROMOLECULES

Zona pellucida intact mouse pre- and post-ovulatory oocytes and zygote s were investigated for permeability to macromolecules using graded ne utral fluorescein isothiocyanate (FITC) dextrans (molecular weight ran ge 3.84-170 kDa) and a range of galactose-binding lectins (molecular w eight range 40-247 kDa). The use of both FITC neutral dextrans and FIT C galactose-binding lectins gave good agreement in the zona pellucida permeability studies. Zona pellucida intact pre- and post-ovulatory oo cytes were permeable to both markers up to a molecular weight range of 170 kDa although movement across the zona pellucida was diminished be tween 100 to 150 kDa with no detectable permeability at molecular weig ht range of 170 kDa. Zygotes demonstrated a decreased zona pellucida p ermeability at around 110 kDa. Two galactose-containing oligosaccharid e-rich zones in the zona pellucida were identified, and changes in zyg ote vitelline membrane galactose-binding lectin affinity were detected . (C) 1995 Wiley-Liss, Inc.