Oocyte Galα1,3Gal Epitopes Implicated in Sperm Adhesion to the Zona Pellucida Glycoprotein ZP3 Are Not Required for Fertilization in the Mouse (*)
- From the (1) Department of Pathology, University of Michigan, Ann Arbor, Michigan 48109 and the
- (2) Howard Hughes Medical Institute, Ann Arbor, Michigan 48109-0650
Abstract
The Galα1
3Gal structure is displayed on the zona pellucida glycoprotein ZP3 on murine oocytes. This trisaccharide has been implicated
in sperm-zona pellucida adhesive events thought to be essential to fertilization in the mouse. To determine directly if this
molecule is required for fertilization, we have generated mice that are deficient in a gene (α1,3GT) encoding the UDP-Gal:β-D-Gal-α1
3Gal-galactosyltransferase enzyme responsible for Galα1
3Gal synthesis and expression. These mice develop normally and exhibit no gross phenotypic abnormalities. The Galα1
3Gal epitope is absent from the vascular endothelium and other tissues in α1,3GT (−/−) adult mice. By contrast, α1,3GT (−/−)
mice, like humans, develop naturally occurring anti-α-galactoside antibodies normally absent in wild type mice. Female α1,3GT
(−/−) mice yield oocytes that are devoid of the Galα1
3Gal epitope; however, these mice are fully fertile. These observations indicate that the Galα1
3Gal moiety is not essential to sperm-oocyte interactions leading to fertilization or to essentially normal development. They
further suggest that α1,3GT (−/−) mice will find utility for exploring approaches to diminish anti-Gal-dependent hyperacute
xenograft rejection, which presents a major barrier to the use of porcine and other non-primate organs for xenotransplantation
in humans.
Footnotes
-
↵§ Associate Investigator of the Howard Hughes Medical Institute.
-
↵* The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
-
↵1 The abbreviations used are:
- α1,3GT
-
UDP-Gal:β-D-Gal-α1
3Gal-galactosyltransferase
- ES
-
embryonic stem cell(s)
- BSA
-
bovine serum albumin
- PBS
-
phosphate-buffered saline
- FITC
-
fluorescein isothiocyanate
- BSIB4
-
B. simplicifolia isolectin B4.
-
- Received June 28, 1995.
- © 1995 by The American Society for Biochemistry and Molecular Biology, Inc.
