During mammalian fertilization, germ cell-specific hyaluronidases, such as sperm adhesion molecule 1 (SPAM1) and hyaluronoglucosaminidase 5 (Hyal5), are important for the dispersal of the cumulus mass. In this study, we demonstrated that bull Hyal5 is a single copy gene on chromosome 4 that is expressed specifically in the testis. In addition, we expressed recombinant bull SPAM1 and Hyal5 in human embryonic kidney 293T cells and showed that these enzymes possessed hyaluronidase activity. We also demonstrated that a polyclonal antibody against bull sperm hyaluronidase inhibits sperm-egg interactions in an in vitro fertilization (IVF) assay. Our results suggested that bull Hyal5 may have a critical role in bull fertilization.

ABSTRACT   INTRODUCTION   MATERIALS AND METHODS    Total RNA Extraction and Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR)    Southern Blot Analysis    Antibody    Preparation of Protein Extracts    Sodium Dodecyl Sulfate-polyacrylamide Gel Electrophoresis(SDS-PAGE) and Western Blot Analysis    Expression of Bovine PH-20 and Hyal5    Zymography    Dispersal of Cumulus Cells In Vitro    In Vitro Maturation (IVM) and In Vitro Fertilization(IVF)    Statistical Analysis   RESULTS    Expression of PH-20 and Hyal5    Sequence Analysis of Hyal5 and SPAM1    SPAM1 and Hyal5 are Single Copy Genes in the Bovine Genome    Importance of Sperm Hyaluronidase in Sperm-Oocyte Interaction   DISCUSSION   REFERENCES

• Ekyune Kim(College of Pharmacy, Catholic University of Daegu)
• Kyu-Tae Chang(National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology) Corresponding author