In its early and most critical stages, human reproduction requires precise, vital functions. The role of one sperm-delivered protein, which is crucial to the process, is being closely observed by scientists from the United States and Canada. Lab tests in recent years have produced valuable information and hopes of regulating that protein to enhance fertility.
Peter Sutovsky, assistant professor of animal sciences in the University of Missouri-Columbia's College of Agriculture, Food and Natural Resources and assistant professor of clinical obstetrics and gynecology in the School of Medicine, has collaborated with Richard Oko, professor of anatomy and cell biology at Queen's University (Ontario), and other academic researchers examining the role of postacrosomal sheath WW domain binding protein (PAWP), which during fertilization must function properly to initiate the reproduction process. If not, reproduction won't occur, Sutovsky said.
PAWP's role is one of the earliest reproduction requirements, he said. The protein is located inside of the sperm head and separates from the sperm shortly after the sperm fuses with the egg cell. PAWP activates the fertilized egg to divide and become an embryo, and triggers a defense mechanism that stops additional sperm from penetrating the egg cell.
Understanding of the PAWP protein is extremely important for fertility purposes and families wanting children. Where there are low levels of this protein, fertilization doesn't function properly. Therefore, regulation of this protein may increase the chances of pregnancy. Additional doses of the protein would be included during intracytoplasmic sperm injection (ICSI) – when a single sperm is injected directly into an egg cell. ICSI is the most commonly used technique to overcome male infertility problems.
"This is a well defined case," Sutovsky said. "During infertility, when the protein is lacking or not functioning properly, we can supply a synthetic version for assisted fertilization."
An abstract of the study, "PAWP, A Sperm Specific WW-Domain Binding Protein, Promotes Meiotic Resumption and Pronuclear Development during Fertilization," has been published online by the Journal of Biological Chemistry and is available at: http://www.jbc.org/cgi/content/abstract/M609132200v1.