Functional characterization of double-knockout mouse sperm lacking SPAM1 and ACR or SPAM1 and PRSS21 in fertilization

J Reprod Dev. 2012;58(3):330-7. doi: 10.1262/jrd.2011-006. Epub 2012 Feb 24.


Mammalian fertilization requires sperm to penetrate the cumulus to reach the oocyte. Although sperm hyaluronidase has long been believed to participate in the penetration process, our previous works revealed that neither of two sperm hyaluronidases, SPAM1 and HYAL5, are essential for fertilization. In this study, we have produced double-knockout mice lacking SPAM1 and either one of two sperm serine proteases, ACR and PRSS21, and characterized the mutant sperm. The SPAM1/ACR- and SPAM1/PRSS21-deficient males were fertile, whereas epididymal sperm of the mutant mice exhibited a reduced capacity to fertilize the oocytes in vitro. Despite normal motility, the ability of sperm to traverse the cumulus matrix was more severely impaired by the loss of SPAM1 and ACR or SPAM1 and PRSS21 than by the loss of only SPAM1. Moreover, SPAM1/ACR- and SPAM1/PRSS21-deficient sperm accumulated on the surface (outer edge) of the cumulus more abundantly than SPAM1-deficient sperm. These results suggest that ACR or PRSS21 or both may function cooperatively with SPAM1 in sperm/cumulus penetration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acrosin / genetics*
  • Animals
  • Cell Adhesion Molecules / genetics*
  • Cumulus Cells / cytology*
  • Epididymis / metabolism
  • Female
  • Fertilization*
  • GPI-Linked Proteins / genetics
  • Gene Expression Regulation
  • Hyaluronoglucosaminidase / genetics*
  • Male
  • Mice
  • Mice, Inbred ICR
  • Mice, Knockout
  • Oocytes / cytology
  • Oocytes / metabolism
  • Pregnancy
  • Serine Endopeptidases / genetics*
  • Serine Proteases / metabolism
  • Spermatozoa / metabolism*
  • Time Factors


  • Cell Adhesion Molecules
  • GPI-Linked Proteins
  • Hyal5 protein, mouse
  • Hyaluronoglucosaminidase
  • hyaluronidase PH-20
  • Serine Proteases
  • Prss21 protein, mouse
  • Serine Endopeptidases
  • Acrosin