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Biomedical Sciences
Susan S. Suarez, M.S., Ph.D.
Professor of Biomedical Sciences

. Faculty .
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Phone: 607 253 3589
Fax: 607 253 3541

The basic question that we seek to answer is "How do sperm get to the egg?" We have been focusing on how sperm move through the mammalian oviduct (fallopian tube). When sperm reach the oviduct, they are trapped and held in a reservoir and stored there until ovulation. We have learned that sperm are held in the oviductal reservoir by binding to glycoproteins expressed on the surface of the epithelium lining the oviduct. We have identified complementary proteins on sperm that cause them to bind to the glycoproteins on the oviductal epithelium. Now we are seeking to determine how sperm are kept alive and fertile during storage in the reservoir. When sperm are released from the oviductal reservoir, their flagellar beating pattern switches from symmetrical to asymmetrical. We have demonstrated that this switch, known as hyperactivation, aids the sperm in penetrating mucus in the oviduct and the zona pellucida of the oocyte. Using a high speed imaging system, we determined that intracellular calcium is increased in hyperactivated sperm. Further, we found that the calcium interacts with calmodulin to activate calmodulin kinase II to switch on hyperactivation. We are now seeking to uncover the remaining elements of the signal transduction pathway in sperm that cause hyperactivation.


Publications are listed in PubMed.




  • Vet Med 510 - "The Animal Body"
    First year foundation course for veterinary students which encompasses the disciplines of gross anatomy, microscopical anatomy, embryology, radiology, and introductory clinical sciences
  • Bio Ap 413 - "Histology: the Biology of Tissues"