Abstract Mouse Oviduct Specific Glycoprotein (OGP) is an Egg-Associated ZP3-Independent Sperm Adhesion Ligand
By Robert John Lyng Mouse sperm-egg binding requires a multiplicity of receptor-ligand interactions, including an oviduct-derived, basic, high molecular weight, wheat germ agglutinin (WGA)-binding, glycoprotein that associates with the egg coat after ovulation. Herein we report the purification and identification of a sperm-binding ligand. WGA-reactive, high molecular weight glycoproteins isolated from superovulated mouse oviduct lysates competitively inhibit sperm-egg binding in vitro. Within this heterogeneous glycoprotein preparation, a distinct 220 kDa protein selectively binds to sperm surfaces. Sequencing of the 220 kDa protein identified it as Oviduct-Specific Glycoprotein (OGP). OGP was confirmed as a sperm-binding ligand by the following three results: specific immuno- depletion of OGP from the denatured oviduct lysates completely abolished the sperm- binding activity, the immunoprecipitated OGP was capable of competitively inhibiting sperm-egg binding, and natively purified OGP also competitively inhibits sperm-egg binding. As expected, the secretory cells of the oviduct fimbriae and infundibulum express OGP; however, contrary to previous reports, OGP is found associated with both the zona pellucida and the perivitelline space of oocytes. Western blot analysis and lectin affinity chromatography demonstrates that whereas the bulk of OGP remains soluble in the ampullar fluid, distinct OGP glycoforms associate with the cumulus matrix, zona pellucida and perivitelline space. In this regard, the OGP sperm-binding activity is restricted to a PNA-reactive glycoform that shows preferential binding to the sperm surface, zona pellucida and perivitelline space, relative to other more abundant glycoforms that do not localize to these domains nor have sperm-binding activity. Interestingly, pretreatment of 2-cell embryos, which do not normally bind sperm, with PNA-reactive OGP stimulates sperm binding. Finally, the sperm-binding activity of the PNA-reactive OGP is shown to be carbohydrate dependent.
Table of Contents
Table of Contents
CHAPTER 1: INTRODUCTION 1 1.1 Introduction to Dissertation 1 1.2 Mammalian Fertilization 2 1.2.1 Overview 2 1.2.2 Sperm-Oocyte Interactions 7 220.127.116.11 Sperm-ZP recognition and binding 7 18.104.22.168.1 Zona Pellucida 3 (ZP3) 7 22.214.171.124.2 1,4-Galactosyltransferase 1 (GalT 1) 8 126.96.36.199.3 SED1 10 188.8.131.52.4 Cyritestin 11 184.108.40.206.5 Glycodelins and Fucosyltransferase 5 (FUT5) 12 220.127.116.11.6 Arylsulfatase-A and SGG glycolipid 13 18.104.22.168 Sperm-ZP secondary interactions 14 22.214.171.124.1 Zona Pellucida 2 (ZP2) 14 126.96.36.199.2 sp56 15 188.8.131.52.3 Zonadhesin 16 184.108.40.206 Sperm-egg plasma membrane binding and fusion 17 220.127.116.11.1 CD9 17 18.104.22.168.2 Izumo 18 22.214.171.124.3 CRISP-1 19 126.96.36.199.4 SLLP-1 20
About this Dissertation
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|Mouse Oviduct Specific Glycoprotein (OGP) is an Egg-AssociatedZP3-Independent Sperm Adhesion Ligand ()||2018-08-28 15:17:18 -0400||