The very basic question that Professor Suarez seeks to answer in her research is "How do sperm get to the egg?" More specifically, she has been investigating the regulation of movement of sperm in the mammalian oviduct. When sperm reach the oviduct, they are held in a reservoir at its entrance and maintained there until ovulation. She and her team mates have learned that sperm are held in the oviduct by binding specifically to sugars of glycoproteins on the surface of the oviductal epithelium. They are now seeking to identify the glycoproteins, and to learn how sperm are released from the reservoir. Another aspect of sperm movement regulation is control of flagellar beating patterns. When sperm are released from the oviductal reservoir, their flagellar beating switches from symmetrical to asymmetrical. They have demonstrated that this switch, known as hyperactivation, aids the sperm in penetrating mucus in the oviduct and the glycoproteinaceous shell of the oocyte. By developing a high speed imaging system, the group has determined that intracellular calcium is increased in hyperactivated sperm and that calcium oscillates within the flagellum. They are now seeking to determine how hyperactivation is initiated and how calcium reaches the movement-producing machinery of the flagellum to initiate hyperactivation.